fix crash when switching phonon backends on the fly, remember to stop libvlc...

fix crash when switching phonon backends on the fly, remember to stop libvlc media player before releasing it
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

bindings/phonon/vlc/vlcmediaobject.cpp

@@ -55,7 +55,9 @@ VLCMediaObject::VLCMediaObject(QObject * parent)
 
 VLCMediaObject::~VLCMediaObject()
 {
-//    unloadMedia();
+    unloadMedia();
+
+    libvlc_media_player_stop(p_vlc_media_player, vlc_exception); // ensure that we are stopped
     libvlc_media_player_release(p_vlc_media_player);
 }