macosx: video effects panel: add missing vlc_object_release

(cherry picked from commit bec9b75ce8156585bf57642798f3f09d83d189d9)

Conflicts:
	modules/gui/macosx/VideoEffects.m

modules/gui/macosx/VideoEffects.m

@@ -584,6 +584,7 @@ static VLCVideoEffects *_o_sharedInstance = nil;
         var_SetBool( p_filter, psz_name, b_value );
         config_PutInt( p_intf, psz_name, b_value );
         vlc_object_release( p_vout );
+        vlc_object_release( p_filter );
     }
 }