The "default" storageclass rather than a hard code one "standard" should be used in the volume claim of minio

[ywk253100]

kubectl describe statefulset sz-harbor-cluster-minio-zone-harbor -n harbor
Name:               sz-harbor-cluster-minio-zone-harbor
Namespace:          harbor
CreationTimestamp:  Wed, 21 Oct 2020 02:52:23 +0000
Selector:           v1.min.io/tenant=sz-harbor-cluster-minio,v1.min.io/zone=zone-harbor
Labels:             <none>
Annotations:        <none>
Replicas:           2 desired | 0 total
Update Strategy:    RollingUpdate
Pods Status:        0 Running / 0 Waiting / 0 Succeeded / 0 Failed
Pod Template:
  Labels:  app=minio
           type=harbor-cluster-minio
           v1.min.io/tenant=sz-harbor-cluster-minio
           v1.min.io/zone=zone-harbor
  Containers:
   minio:
    Image:      minio/minio:RELEASE.2020-08-13T02-39-50Z
    Port:       9000/TCP
    Host Port:  0/TCP
    Args:
      server
      --certs-dir
      /tmp/certs
    Limits:
      cpu:     500m
      memory:  500Mi
    Requests:
      cpu:     200m
      memory:  200Mi
    Liveness:  http-get http://:9000/minio/health/live delay=120s timeout=1s period=60s #success=1 #failure=1
    Environment:
      MINIO_BROWSER:                 on
      MINIO_UPDATE:                  on
      MINIO_UPDATE_MINISIGN_PUBKEY:  RWTx5Zr1tiHQLwG9keckT0c45M3AGeHD6IvimQHpyRywVWGbP1aVSGav
      MINIO_ARGS:                    <set to the key 'MINIO_ARGS' in secret 'minio-args-secret'>  Optional: false
      MINIO_ENDPOINTS:               http://sz-harbor-cluster-minio-zone-harbor-{0...1}.sz-harbor-cluster-minio-hl.harbor.svc.cluster.local/export{0...1}
      MINIO_ACCESS_KEY:              <set to the key 'accesskey' in secret 'sz-harbor-cluster-minio-creds'>  Optional: false
      MINIO_SECRET_KEY:              <set to the key 'secretkey' in secret 'sz-harbor-cluster-minio-creds'>  Optional: false
    Mounts:
      /export0 from 0 (rw)
      /export1 from 1 (rw)
  Volumes:  <none>
Volume Claims:
  Name:          0
  StorageClass:  standard
  Labels:        <none>
  Annotations:   <none>
  Capacity:      100Mi
  Access Modes:  [ReadWriteOnce]
  Name:          1
  StorageClass:  standard
  Labels:        <none>
  Annotations:   <none>
  Capacity:      100Mi
  Access Modes:  [ReadWriteOnce]

Currently the field StorageClass in the following claim is hard code as standard, this causes failure in the k8s cluster that has no StorageClass named standard. The StorageClass field should be empty which will use the default one

...
Volume Claims:
  Name:          0
  StorageClass:  standard
...