Fix OC ceph deploy - roles data only when provided
Fix OC ceph deploy - roles data only when provided

Roles data files does not exist in all cases,
and when they don't ceph deploy fails:

"Roles Data file not found --roles-data /home/stack/virt/roles/roles_data.yaml."

So this parameter should be passed only when roles_data.yaml file exists.

Change-Id: I4b39add6bfe9ccdb04f5f9728f336065c6fc5f82

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