Use network name instead of ID for fixed_network
Use network name instead of ID for fixed_network

Instance IP address is obtained by:
IP: {get_attr: [host, networks, {get_param: fixed_network}, 0]}

But it seems that in some openstack environments (older heat version?)
this doesn't if fixed_network is ID. If fixed_network is network's name
it works in  all tested openstack environments.

markllama/openshift-on-openstack,redhat-openstack/openshift-on-openstack,markllama/openshift-on-openstack,BBVA/openshift-on-openstack,BBVA/openshift-on-openstack,redhat-openstack/openshift-on-openstack