Fix test_wrong_server_reply()

    @pytest.mark.parametrize("bad_data", ["not a dict", {"wrong": "dict"}])
    def test_wrong_server_reply(bad_data, manager_factory):
        """
        A response that is not a dictionary or that does not contain
        the right entries should not raise an exception.
        It should not modify the attributes we use to track the last
        synchronization either.
        """
    
        def bad_get_changes(*args, **kwargs):
            return bad_data
    
        manager, engine = manager_factory()
>       sync_date = engine._remote_watcher._last_sync_date
E       AttributeError: 'Engine' object has no attribute '_remote_watcher'