do not pass complete track data to exporter factory method just to knwo if there is more then one track to export

src/main/java/de/dennisguse/opentracks/fragments/ExportProgressDialogFragment.java

@@ -206,7 +206,7 @@ public class ExportProgressDialogFragment extends DialogFragment {
         }
 
         private Boolean exportTrack(Context context, Track track) {
-            TrackExporter trackExporter = trackFileFormat.newTrackExporter(context, new Track[]{track});
+            TrackExporter trackExporter = trackFileFormat.newTrackExporter(context);
 
             //TODO Move to helper function
             String fileName = track.getId() + "." + trackFileFormat.getExtension();