Fix a few issues with Patroni API (#2116)
Fix a few issues with Patroni API (#2116)

1. The `client_address` tuple may have more than two elements in case of IPv6
2. Return `cluster_unlocked` only when the value is true and handle it respectively in the do_GET_metrics()
3. Return `cluster_unlocked` and `dcs_last_seen` even if Postgres isn't running/queries timing out

Close https://github.com/zalando/patroni/issues/2113
zalando/patroni,zalando/patroni