mm_glib_source: Ignore error when enabling AGPS MSB

AGPS enablement sometimes timeouts on Oneplus 6.

Also improve logging of NMEA initialization errors.

satellite/application.py

@@ -261,8 +261,8 @@ class SatelliteApp(Gtk.Application):
                 dtext = "Please unlock the Modem"
             else:
                 fatal = isinstance(e, gi.repository.GLib.GError)
-                self.log_msg("Error initializing NMEA source")
                 etext = str(e)
+                self.log_msg(f"Error initializing NMEA source: {etext}")
                 dtext = etext if etext else (
                     "Could not find or initialize NMEA source")
             dialog = Gtk.MessageDialog(

satellite/mm_glib_source.py

@@ -75,6 +75,10 @@ class ModemManagerGLibNmeaSource(NmeaSource):
                 raise ModemLockedError from e
             else:
                 raise e
+        except gi.repository.GLib.GError as e:
+            # Ignore error on AGPS enablement by this hack
+            if 'agps-msb' not in str(e):
+                raise e
 
         self.mlocation.set_gps_refresh_rate_sync(self.refresh_rate, None)
         self.mlocation.connect('notify::location', self.update_callback)