nova_libvirt_init_secret: add net=host
nova_libvirt_init_secret: add net=host

Required by podman to create the virsh secrets.
Somehow it was hidden by podman.

Change-Id: I0e956e59fc8729bb31f2e4e000597db2611849d9

openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates