Update subunit_describe_calls about new ports

This commit updates the default version explanation in
subunit_describe_calls. It seems the 'Firewalls and default ports'
is moved to a new location. In Newton it was here [0] but from Ocata
it gives 404 [1] because it got moved to [2].

And this commit also fixes some markups as inline literals.

[0] https://docs.openstack.org/newton/config-reference/firewalls-default-ports.html
[1] https://docs.openstack.org/ocata/config-reference/
[2] https://docs.openstack.org/install-guide/firewalls-default-ports.html

Change-Id: I82bb3c5bbeaa4de04f607266311e8452e25ce6b5
1 file changed