Included CEPH_USER attr from datastore to be used by ONE Ceph remotes

Modified 2 lines and rados command to take into account the POOL_NAME and CEPH_USER from the datastore template.

At this moment all Ceph remotes are using Ceph admin privileges. This could be a sec. issue, CEPH_USER should be a mandatory param into Ceph datastores and it should be used by Ceph remotes by default.