Remove hard-coded port 6443 in auth

[MichaelClifford]

Based on user feedback, we realized that hard coding the OpenShift server port was causing issues with some users preventing them from being able to log in.

This PR simple removes the :6443 suffix from server parameter so that the port must be explicitly included.

We can add future PR's to include some more sophisticated server address parsing and error handling.

[anishasthana]

/lgtm

[anishasthana]

We should follow up with a PR later to make the server string logic a little more intelligent, something like

if len(self.server.split(":")) > 1:
    # Use server string
else:
   # User server string + :6443

[anishasthana]

/lgtm