macosx: Don't send nil as notification object for...

macosx: Don't send nil as notification object for VLCLibraryModelVideoMediaListUpdated and VLCLibraryModelAudioMediaListUpdated in VLCLibraryModel's dropCaches

Signed-off-by: Claudio Cambra <developer@claudiocambra.com>

modules/gui/macosx/library/VLCLibraryModel.m

@@ -513,8 +513,8 @@ static void libraryCallback(void *p_data, const vlc_ml_event_t *p_event)
     _cachedArtists = nil;
     _cachedAudioMedia = nil;
 
-    [_defaultNotificationCenter postNotificationName:VLCLibraryModelVideoMediaListUpdated object:nil];
-    [_defaultNotificationCenter postNotificationName:VLCLibraryModelAudioMediaListUpdated object:nil];
+    [_defaultNotificationCenter postNotificationName:VLCLibraryModelVideoMediaListUpdated object:self];
+    [_defaultNotificationCenter postNotificationName:VLCLibraryModelAudioMediaListUpdated object:self];
 }
 
 @end