fix(core): Ticket serializer org validator to access correct data

ref: #248 #368 #377

app/core/serializers/ticket.py

@@ -207,9 +207,7 @@ class TicketModelSerializer(TicketBaseSerializer):
 
             if self.instance.pk is not None:
 
-                if 'organization' in self.get_user_changed_fields:
+                if 'organization' in self.initial_data:
-
-                    if self.field_edited('organization'):
 
                         is_valid = False