fix what interface we derive values from when setting up a subnet.

it should be foreman's local secondary nic, not a reference to a
yet-to-exist nic on an openstack host.
Merge pull request #43 from cwolferh/nic_fix

fix what interface we derive values from when setting up a subnet.
Automatic commit of package [openstack-foreman-installer] release [0.0.18-1].
BZ978568 - Fixing setsebool for httpd on controller nodes