This has the biggest impact on enterprise test cases that use namespaced
registrations, which prior to this change sometimes failed the initial
registration because the namespace was not yet created.
A port can be sent in the Host header as defined in the HTTP RFC, so we
take any hosts that we want to match traffic to and also add another
host with the listener port added.
Also fix an issue with envoy integration tests not running the
case-ingress-gateway-tls test.
