Fix wrong arguments being passed to BlacklistingAgentWrapper (#9098)

A reactor was being passed instead of a whitelist for the BlacklistingAgentWrapper
used by the WellyKnownResolver. This coulld cause exceptions when attempting to
connect to IP addresses that are blacklisted, but in reality this did not have any
observable affect since this code is not used for IP literals.

changelog.d/9098.misc

@@ -0,0 +1 @@
+Fix the wrong arguments being passed to `BlacklistingAgentWrapper` from `MatrixFederationAgent`. Contributed by Timothy Leung.

synapse/http/federation/matrix_federation_agent.py

@@ -102,7 +102,6 @@ class MatrixFederationAgent:
                         pool=self._pool,
                         contextFactory=tls_client_options_factory,
                     ),
-                    self._reactor,
                     ip_blacklist=ip_blacklist,
                 ),
                 user_agent=self.user_agent,