Backout unrealted change.

Author: clokep

tests/handlers/test_federation.py

@@ -251,9 +251,7 @@ def _build_and_send_join_event(self, other_server, other_user, room_id):
         join_event.signatures[other_server] = {"x": "y"}
         with LoggingContext("send_join"):
             d = run_in_background(
-                self.handler.on_send_membership_event,
-                other_server,
-                join_event,
+                self.handler.on_send_membership_event, other_server, join_event
             )
         self.get_success(d)