fixup spiral ??

conformal.cpp

@@ -913,7 +913,7 @@ namespace conformal {
       dialog::addSelItem(XLAT("spiral angle"), fts(spiral_angle), 'x');
       dialog::add_action([](){
         dialog::editNumber(spiral_angle, 0, 360, 15, 0, XLAT("spiral angle"), 
-          XLAT("set to 90° for the ring projection"
+          XLAT("set to 90° for the ring projection")
           );
         });