fix storage info output with unordered endpoints arguments (#9610)

Shuffling arguments that we pass to MinIO server are supported. However,
when that happens, Prometheus returns wrong information about disks usage
and online/offline status.

The commit fixes the issue by avoiding relying on xl.endpoints since
it is not ordered.

cmd/storage-rest-client.go

@@ -147,6 +147,10 @@ func (client *storageRESTClient) IsOnline() bool {
 	return atomic.LoadInt32(&client.connected) == 1
 }
 
+func (client *storageRESTClient) IsLocal() bool {
+	return false
+}
+
 func (client *storageRESTClient) Hostname() string {
 	return client.endpoint.Host
 }