Unable to find keyring on AuthRegistry

Ceph radosgw unable to start due to no mon-config and no authentication data in keyring.

Excerpt from the journal bellow:
```
abr 01 07:42:08 juju-eb4447-1-lxd-2 systemd[1]: Started Ceph rados gateway.
abr 01 07:42:08 juju-eb4447-1-lxd-2 sudo[165155]: pam_unix(sudo:session): session closed for user root
abr 01 07:42:08 juju-eb4447-1-lxd-2 radosgw[165158]: 2022-04-01T11:42:08.657+0000 7fd84e410b40 -1 auth: unable to find a keyring on /var/lib/ceph/radosgw/ceph-rgw.juju-eb4447-1-lxd-2/keyring: (2) No suc>
abr 01 07:42:08 juju-eb4447-1-lxd-2 radosgw[165158]: 2022-04-01T11:42:08.657+0000 7fd84e410b40 -1 AuthRegistry(0x557349063618) no keyring found at /var/lib/ceph/radosgw/ceph-rgw.juju-eb4447-1-lxd-2/keyr>
abr 01 07:42:08 juju-eb4447-1-lxd-2 radosgw[165158]: 2022-04-01T11:42:08.657+0000 7fd84e410b40 -1 auth: unable to find a keyring on /var/lib/ceph/radosgw/ceph-rgw.juju-eb4447-1-lxd-2/keyring: (2) No suc>
abr 01 07:42:08 juju-eb4447-1-lxd-2 radosgw[165158]: 2022-04-01T11:42:08.657+0000 7fd84e410b40 -1 AuthRegistry(0x7fffe251c3d0) no keyring found at /var/lib/ceph/radosgw/ceph-rgw.juju-eb4447-1-lxd-2/keyr>
abr 01 07:42:08 juju-eb4447-1-lxd-2 radosgw[165158]: failed to fetch mon config (--no-mon-config to skip)
abr 01 07:42:08 juju-eb4447-1-lxd-2 systemd[1]: <email address hidden>: Main process exited, code=exited, status=1/FAILURE
abr 01 07:42:08 juju-eb4447-1-lxd-2 systemd[1]: <email address hidden>: Failed with result 'exit-code'.
abr 01 07:42:08 juju-eb4447-1-lxd-2 systemd[1]: <email address hidden>: Scheduled restart job, restart counter is at 1.
abr 01 07:42:08 juju-eb4447-1-lxd-2 systemd[1]: Stopped Ceph rados gateway.
abr 01 07:42:08 juju-eb4447-1-lxd-2 systemd[1]: Started Ceph rados gateway.
abr 01 07:42:09 juju-eb4447-1-lxd-2 radosgw[165167]: 2022-04-01T11:42:09.017+0000 7fa91a403b40 -1 auth: unable to find a keyring on /var/lib/ceph/radosgw/ceph-rgw.juju-eb4447-1-lxd-2/keyring: (2) No suc>
abr 01 07:42:09 juju-eb4447-1-lxd-2 radosgw[165167]: 2022-04-01T11:42:09.017+0000 7fa91a403b40 -1 AuthRegistry(0x556c0a3e5618) no keyring found at /var/lib/ceph/radosgw/ceph-rgw.juju-eb4447-1-lxd-2/keyr>
abr 01 07:42:09 juju-eb4447-1-lxd-2 radosgw[165167]: 2022-04-01T11:42:09.021+0000 7fa91a403b40 -1 auth: unable to find a keyring on /var/lib/ceph/radosgw/ceph-rgw.juju-eb4447-1-lxd-2/keyring: (2) No suc>
abr 01 07:42:09 juju-eb4447-1-lxd-2 radosgw[165167]: 2022-04-01T11:42:09.021+0000 7fa91a403b40 -1 AuthRegistry(0x7fffef68f5b0) no keyring found at /var/lib/ceph/radosgw/ceph-rgw.juju-eb4447-1-lxd-2/keyr>
abr 01 07:42:09 juju-eb4447-1-lxd-2 radosgw[165167]: failed to fetch mon config (--no-mon-config to skip)
abr 01 07:42:09 juju-eb4447-1-lxd-2 systemd[1]: <email address hidden>: Main process exited, code=exited, status=1/FAILURE
abr 01 07:42:09 juju-eb4447-1-lxd-2 systemd[1]: <email address hidden>: Failed with result 'exit-code'.
abr 01 07:42:09 juju-eb4447-1-lxd-2 systemd[1]: <email address hidden>: Scheduled restart job, restart counter is at 2.
abr 01 07:42:09 juju-eb4447-1-lxd-2 systemd[1]: Stopped Ceph rados gateway.
```

Seen on: https://solutions.qa.canonical.com/testruns/testRun/f18f697f-46dd-48f0-bca4-5ba88c252f9e
Artifacts for this run: https://oil-jenkins.canonical.com/artifacts/f18f697f-46dd-48f0-bca4-5ba88c252f9e/index.html
Relevant juju artifacts: https://oil-jenkins.canonical.com/artifacts/f18f697f-46dd-48f0-bca4-5ba88c252f9e/generated/generated/openstack/juju-crashdump-openstack-2022-04-01-15.00.13.tar.gz