add if None for watch in queue_notification_for_watch

changedetectionio/update_worker.py

@@ -81,6 +81,7 @@ class update_worker(threading.Thread):
             'watch_url': watch.get('url') if watch else None,
         })
 
+        if watch:
             n_object.update(watch.extra_notification_token_values())
 
         logger.trace(f"Main rendered notification placeholders (diff_added etc) calculated in {time.time()-now:.3f}s")