podcast: save configuration when adding/removing podcast from the dialog.

(cherry picked from commit f471df4d)
Signed-off-by: Rémi Duraffort <ivoire@videolan.org>

modules/gui/qt4/dialogs/podcast_configuration.cpp

@@ -74,6 +74,7 @@ void PodcastConfigDialog::accept()
     }
     const char *psz_urls = qtu( urls );
     config_PutPsz( p_intf, "podcast-urls", psz_urls );
+    config_SaveConfigFile( p_intf, "podcast" );
     vlc_object_t *p_obj = (vlc_object_t*)
                           vlc_object_find_name( p_intf->p_libvlc,
                                                 "podcast", FIND_CHILD );