fix(Tacking): check if uri is hierarchical

Checks if the given uri is hierarchical, as otherwise the
`getQueryParameterNames` function will throw an exception.

mastodon/src/main/java/org/joinmastodon/android/utils/Tracking.java

@@ -64,7 +64,7 @@ public class Tracking{
  @NonNull
  public static String removeTrackingParameters(@NonNull String url){
  Uri uri=Uri.parse(url);
- if(uri==null)
+ if(uri==null || !uri.isHierarchical())
  return url;
  Uri.Builder uriBuilder=uri.buildUpon().clearQuery();