do not propagate tags

src/algorithms/signal_source/adapters/zmq_signal_source.cc

@@ -44,6 +44,7 @@ ZmqSignalSource::ZmqSignalSource(const ConfigurationInterface* configuration,
             LOG(INFO) << "Connecting to ZMQ pub at " << endpoint;
             // work around gnuradio interface deficiency
             d_source_block = gr::zeromq::sub_source::make(d_item_size, vlen, const_cast<char*>(endpoint.data()), timeout_ms, pass_tags, hwm);
+	    d_source_block->set_tag_propagation_policy(TPP_DONT); // GNSS-SDR doesn't do well with tags/
         }
     else
         {