[ceph] Deploy ceph failed at controller node for multiple node
[ceph] Deploy ceph failed at controller node for multiple node

Controller node wouldn't install libvirt package. The package will only
been installed at nodes which had enable nova-compute.
We only need to configure libvirt secret if it had enable nova-compute.

Change-Id: I9cd6baf1820ce9f71c276d7e8b670307833578a5
Closes-Bug: 1515960

nawawi/openstack,richliu/devstack,samgoon/devstack,avvocatodemarchis/devstack,bswartz/devstack,dirkmueller/devstack,mssumanth/devstack,bswartz/devstack,dtroyer/devstack,noironetworks/devstack,group-policy/devstack,noironetworks/devstack,avvocatodemarchis/devstack,bigswitch/devstack,openstack-dev/devstack,dtroyer/devstack,Mahito/devstack,Mahito/devstack,samgoon/devstack,bigswitch/devstack,nawawi/openstack,dirkmueller/devstack,richliu/devstack,openstack-dev/devstack,group-policy/devstack,mssumanth/devstack