mon: only put mon initial key in mon kv when cephx is enabled
mon: only put mon initial key in mon kv when cephx is enabled

Task put initial mon keyring in mon kv store from
ceph-mon/tasks/ceph_keys.yml is failing when cephx is disabled. The root
cause is that variable monitor_keyring is not populated by any task from
deploy_monitors.yml.

Fixes: #1211

Signed-off-by: Sébastien Han <62d754cc350e84d3b1c32ae79f976f5348e74a40@redhat.com>

ceph/ansible-ceph-mon