Description of problem:
Create a StorageClass for gluster provisioner, setting its gidMin to 0, gidMax to 1. When creating a PVC, the PV could not be provisioned. An error logged 'Failed to provision volume with StorageClass "sc1": StorageClass for provisioner "kubernetes.io/glusterfs" must have gidMax value >= gidMin'.

Version-Release number of selected component (if applicable):
openshift v3.4.0.33+71c05b2
kubernetes v1.4.0+776c994
etcd 3.1.0-rc.0

How reproducible:
Always

Steps to Reproduce:
1. Create a StorageClass, setting its gidMin to 0, gidMax to 1. 
apiVersion: storage.k8s.io/v1beta1
kind: StorageClass
metadata:
  name: sc1
provisioner: kubernetes.io/glusterfs
parameters:
  resturl: "<hidden>"
  restuser: "xxx"
  restuserkey: "xxx"
  gidMin: "0"
  gidMax: "1"
provisioner: kubernetes.io/glusterfs

2. Create a PVC that uses this StorageClass to provision volumes.
{
   "kind": "PersistentVolumeClaim",
   "apiVersion": "v1",
   "metadata": {
     "name": "c1",                                                                                                                                 
     "annotations": {
     "volume.beta.kubernetes.io/storage-class": "sc1"
     }
   },
   "spec": {
     "accessModes": [
       "ReadWriteOnce"
     ],
     "resources": {
       "requests": {
         "storage": "10Gi"
       }
     }
   }
}

3. oc describe pvc c1

Actual results:
After step 3:
oc describe pvc c1                
Name:		c1
Namespace:	jhou
StorageClass:	sc1
Status:		Pending
Volume:		
Labels:		<none>
Capacity:	
Access Modes:	
Events:
  FirstSeen	LastSeen	Count	From				SubobjectPath	Type		Reason			Message
  ---------	--------	-----	----				-------------	--------	------			-------
  5m		1s		25	{persistentvolume-controller }			Warning		ProvisioningFailed	Failed to provision volume with StorageClass "sc1": StorageClass for provisioner "kubernetes.io/glusterfs" must have gidMax value >= gidMin


Expected results:
Error description should be instructive, the gidMax is already greater than gidMin.

Additional info: