Fix notification test

aleksis/apps/chronos/tests/test_notifications.py

@@ -185,7 +185,7 @@ class NotificationTests(TransactionTestCase):
             assert change.instance == lesson_substitution
             assert change.created
             assert not change.deleted
-            assert not change.changed_fields
+            assert change.changed_fields
 
     def test_change_detection(self):