Fixes commons-app#3371 (commons-app#3372)

* Is UserBrowsing should first check if last known location is non-null before checkig if last location and current locations are close

Author: ashishkumar468

app/src/main/java/fr/free/nrw/commons/nearby/fragments/NearbyParentFragment.java

@@ -894,7 +894,7 @@ private void handleLocationUpdate(fr.free.nrw.commons.location.LatLng latLng, Lo
     }
 
     private boolean isUserBrowsing() {
-        boolean isUserBrowsing = !presenter.areLocationsClose(getCameraTarget(), lastKnownLocation);
+        boolean isUserBrowsing = lastKnownLocation!=null && !presenter.areLocationsClose(getCameraTarget(), lastKnownLocation);
         return isUserBrowsing;
     }