Make default ANSIBLE_REMOTE_PORT None

The ansible report port should be None, not 22. Having a default value
of 22 means that -o Port will be appended to the ssh connection all of
the time. This is incorrect when one would like to use something like
an ssh configuration file that calls out a port other than 22.

Part of this change requires that we check that the value is not None
before trying to coerce it into an integer or float.

This is related to https://github.com/ansible/ansible/issues/3352