This change fixes two issues with the recently introduced [0] job that
updates "ceph.conf" inside ceph-client-etc configmap with a discovered
mon_host value:
1. adds missing metadata.labels to the job
2. allows the job to be disabled
(fixes rendering when manifests.job_ns_client_ceph_config = false)
0: https://review.opendev.org/c/openstack/openstack-helm-infra/+/812159
Change-Id: I3a8f1878df4af5da52d3b88ca35ba0b97deb4c35