Only ratelimit when sending the email

If we do the opposite, an event can arrive after or while sending the email and the 3PID invite event will get ratelimited.

synapse/handlers/room_member.py

@@ -773,7 +773,7 @@ class RoomMemberHandler(object):
 
         # We need to rate limit *before* we send out any 3PID invites, so we
         # can't just rely on the standard ratelimiting of events.
-        yield self.base_handler.ratelimit(requester, update=False)
+        yield self.base_handler.ratelimit(requester)
 
         can_invite = yield self.third_party_event_rules.check_threepid_can_be_invited(
             medium, address, room_id,
@@ -935,6 +935,7 @@ class RoomMemberHandler(object):
                 "sender": user.to_string(),
                 "state_key": token,
             },
+            ratelimit=False,
             txn_id=txn_id,
         )