kubernetes: Fix hostnames in the zulip pod
kubernetes: Fix hostnames in the zulip pod

All of the containers are running on a single pod so we can use
localhost to connect to the other services. After this change database
migrations are completing and the app server is starting. It seems
rabbit MQ is still failing to run correctly.

Galexrt/docker-zulip,Galexrt/docker-zulip,Galexrt/docker-zulip