openstack provisioner: no NM_CONTROLLED="no" when not needed
openstack provisioner: no NM_CONTROLLED="no" when not needed

On RHEL/CentOS 8 the old network scripts are just tiny wrappers around
NetworkManager, so there is really no "not controlled by NM".
Without this change, running a command like `ifdown <if>` returns
an error when <if> contains NM_CONTROLLED="no" on such distributions.

Change-Id: Ibe2c3316d8867aeb3f49572efcec1cc4c028b1e8

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared