Because of the recent CRD changes made, the mon count had a minimum of
1, making the configuration of the external cluster impossible. The
operator would fail to add the finalizer:
```
2021-04-29 16:57:38.429451 E | ceph-cluster-controller: failed to reconcile. failed to add finalizer: failed to add finalizer "cephcluster.ceph.rook.io" on "test-external": CephCluster.ceph.rook.io "test-external" is invalid: spec.mon.count: Invalid value: 0: spec.mon.count in body should be greater than or equal to 1
```
We now fixed the CRD as well as adding the CR status.
Signed-off-by: Sébastien Han <seb@redhat.com>