do not send status messages if fragment is destroyed

src/main/java/com/owncloud/android/media/MediaControlView.java

@@ -197,6 +197,10 @@ public class MediaControlView extends FrameLayout /* implements OnLayoutChangeLi
         updatePausePlay();
     }
 
+    public void stopMediaPlayerMessages() {
+        mHandler.removeMessages(SHOW_PROGRESS);
+    }
+
 
     private void initControllerView(View v) {
         mPauseButton = (ImageButton) v.findViewById(R.id.playBtn);

src/main/java/com/owncloud/android/ui/preview/PreviewMediaFragment.java

@@ -580,6 +580,7 @@ public class PreviewMediaFragment extends FileFragment implements
         if (mMediaServiceConnection != null) {
             Log_OC.d(TAG, "Unbinding from MediaService ...");
             if (mMediaServiceBinder != null && mMediaController != null) {
+                mMediaController.stopMediaPlayerMessages();
                 mMediaServiceBinder.unregisterMediaController(mMediaController);
             }
             getActivity().unbindService(mMediaServiceConnection);