message: fix warning alert while putting node in maintenance mode
diff: @@ -41,7 +41,7 @@ const StartNodeMaintenanceModal = withHandlePromise<StartNodeMaintenanceModalPro
  const [cephClusters, loaded] = useK8sWatchResource<K8sResourceKind[]>(cephClusterResource);
  const cephCluster = cephClusters?.[0];
  - const cephClusterHealthy = !cephCluster || cephCluster?.status?.health === 'OK';
  + const cephClusterHealthy = cephCluster?.status?.ceph?.health === 'HEALTH_OK';
  const action = t('metal3-plugin~Start Maintenance');
  return (
  @@ -70,7 +70,7 @@ const StartNodeMaintenanceModal = withHandlePromise<StartNodeMaintenanceModalPro
  />
  </FormGroup>
  </StackItem>
  - {!cephClusterHealthy && (
  + {!!cephCluster && !cephClusterHealthy && (
  <StackItem>
  <Alert
  variant="warning"
  