added KI2D's latest changes to changelog/gt_update

debian/changelog

@@ -4,10 +4,12 @@ gridtracker (1.21.0517) unstable; urgency=medium
   - Fix PSK spot time skew
   - Fix eQSL ADIF support
   - Fix clearing of logs after installing new version of GridTracker
+  - Fix hightlighting whole country of Somalia on map
   [Enhancements]
   - Update Award Tracker with new FT8DMC and European ROS Club awards
   - Improvements to the callroster
   - Make settings icon a toggle that both opens and closes the settings pane
+  - Grid and IP Address Fields are slightly wider
 
  -- Matthew Chambers <nr0q@gridtracker.org> Mon, 17 May 2021 02:30:00 -0000
 gridtracker (1.21.0407) unstable; urgency=medium