Update links

docs/doxygen/Doxyfile.in

@@ -21,7 +21,7 @@
 # that follow. The default is UTF-8 which is also the encoding used for all
 # text before the first occurrence of this tag. Doxygen uses libiconv (or the
 # iconv built into libc) for the transcoding. See
-# http://www.gnu.org/software/libiconv for the list of possible encodings.
+# https://www.gnu.org/software/libiconv for the list of possible encodings.
 
 DOXYFILE_ENCODING      = UTF-8
 
@@ -551,7 +551,7 @@ LAYOUT_FILE            =
 # The CITE_BIB_FILES tag can be used to specify one or more bib files containing
 # the reference definitions. This must be a list of .bib files. The .bib
 # extension is automatically appended if omitted. This requires the bibtex tool
-# to be installed. See also http://en.wikipedia.org/wiki/BibTeX for more info.
+# to be installed. See also https://en.wikipedia.org/wiki/BibTeX for more info.
 # For LaTeX the style of the bibliography can be controlled using
 # LATEX_BIB_STYLE. To use this feature you need bibtex and perl available in the
 # search path. See also \cite for info how to create references.
@@ -623,7 +623,7 @@ INPUT                  = @top_srcdir@/src @top_srcdir@/docs/doxygen/other
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is
 # also the default input encoding. Doxygen uses libiconv (or the iconv built
-# into libc) for the transcoding. See http://www.gnu.org/software/libiconv for
+# into libc) for the transcoding. See https://www.gnu.org/software/libiconv for
 # the list of possible encodings.
 
 INPUT_ENCODING         = UTF-8
@@ -796,7 +796,7 @@ SOURCE_TOOLTIPS        = YES
 # If the USE_HTAGS tag is set to YES then the references to source code
 # will point to the HTML generated by the htags(1) tool instead of doxygen
 # built-in source browser. The htags tool is part of GNU's global source
-# tagging system (see http://www.gnu.org/software/global/global.html). You
+# tagging system (see https://www.gnu.org/software/global/global.html). You
 # will need version 4.8.6 or higher.
 
 USE_HTAGS              = NO
@@ -875,7 +875,7 @@ HTML_STYLESHEET        =
 # The HTML_COLORSTYLE_HUE tag controls the color of the HTML output.
 # Doxygen will adjust the colors in the stylesheet and background images
 # according to this color. Hue is specified as an angle on a colorwheel,
-# see http://en.wikipedia.org/wiki/Hue for more information.
+# see https://en.wikipedia.org/wiki/Hue for more information.
 # For instance the value 0 represents red, 60 is yellow, 120 is green,
 # 180 is cyan, 240 is blue, 300 purple, and 360 is red again.
 # The allowed range is 0 to 359.
@@ -925,8 +925,6 @@ HTML_DYNAMIC_SECTIONS  = NO
 # directory and running "make install" will install the docset in
 # ~/Library/Developer/Shared/Documentation/DocSets so that Xcode will find
 # it at startup.
-# See http://developer.apple.com/tools/creatingdocsetswithdoxygen.html
-# for more information.
 
 GENERATE_DOCSET        = NO
 
@@ -1123,7 +1121,7 @@ FORMULA_FONTSIZE       = 10
 FORMULA_TRANSPARENT    = YES
 
 # Enable the USE_MATHJAX option to render LaTeX formulas using MathJax
-# (see http://www.mathjax.org) which uses client side Javascript for the
+# (see https://www.mathjax.org) which uses client side Javascript for the
 # rendering instead of using prerendered bitmaps. Use this if you do not
 # have LaTeX installed or if you want to formulas look prettier in the HTML
 # output. When enabled you also need to install MathJax separately and
@@ -1133,7 +1131,7 @@ USE_MATHJAX            = @GNSSSDR_USE_MATHJAX@
 
 # When MathJax is enabled you can set the default output format to be used for
 # the MathJax output. See the MathJax site (see:
-# http://docs.mathjax.org/en/latest/output.html) for more details.
+# https://docs.mathjax.org/en/latest/output.html) for more details.
 # Possible values are: HTML-CSS (which is slower, but has the best
 # compatibility), NativeMML (i.e. MathML) and SVG.
 # The default value is: HTML-CSS.
@@ -1149,7 +1147,7 @@ MATHJAX_FORMAT         = HTML-CSS
 # MathJax, but it is strongly recommended to install a local copy of MathJax
 # before deployment.
 
-MATHJAX_RELPATH        = http://cdn.mathjax.org/mathjax/latest
+MATHJAX_RELPATH        = https://cdnjs.com/libraries/mathjax/
 
 # The MATHJAX_EXTENSIONS tag can be used to specify one or more MathJax
 # extension names that should be enabled during MathJax rendering. For example
@@ -1160,7 +1158,7 @@ MATHJAX_EXTENSIONS     =
 
 # The MATHJAX_CODEFILE tag can be used to specify a file with javascript pieces
 # of code that will be used on startup of the MathJax code. See the MathJax site
-# (see: http://docs.mathjax.org/en/latest/output.html) for more details. For an
+# (see: https://docs.mathjax.org/en/latest/output.html) for more details. For an
 # example see the documentation.
 # This tag requires that the tag USE_MATHJAX is set to YES.
 
@@ -1194,7 +1192,7 @@ SERVER_BASED_SEARCH    = NO
 #
 # Doxygen ships with an example indexer (doxyindexer) and search engine
 # (doxysearch.cgi) which are based on the open source search engine library
-# Xapian (see: http://xapian.org/).
+# Xapian (see: https://xapian.org/).
 #
 # See the section "External Indexing and Searching" for details.
 # The default value is: NO.
@@ -1207,7 +1205,7 @@ EXTERNAL_SEARCH        = NO
 #
 # Doxygen ships with an example indexer (doxyindexer) and search engine
 # (doxysearch.cgi) which are based on the open source search engine library
-# Xapian (see: http://xapian.org/). See the section "External Indexing and
+# Xapian (see: https://xapian.org/). See the section "External Indexing and
 # Searching" for details.
 # This tag requires that the tag SEARCHENGINE is set to YES.
 
@@ -1358,7 +1356,7 @@ LATEX_SOURCE_CODE      = NO
 
 # The LATEX_BIB_STYLE tag can be used to specify the style to use for the
 # bibliography, e.g. plainnat, or ieeetr. See
-# http://en.wikipedia.org/wiki/BibTeX and \cite for more info.
+# https://en.wikipedia.org/wiki/BibTeX and \cite for more info.
 # The default value is: plain.
 # This tag requires that the tag GENERATE_LATEX is set to YES.