Do not fail if deployment id not found in license (minio#4767)

SUBNET is being enhanced to generate account-level licenses instead of
deployment-level. So newer licenses may not contain the deployment id.

So validate the deployment id against the cluster only if present in the
license.

cmd/subnet-utils.go

@@ -609,7 +609,7 @@ func validateAndSaveLic(lic, alias string, saveAPIKey bool) string {
  fatalIf(errDummy().Trace(), fmt.Sprintf("License has expired on %s", li.ExpiresAt))
  }
 
- if li.DeploymentID != getAdminInfo(alias).DeploymentID {
+ if len(li.DeploymentID) > 0 && li.DeploymentID != getAdminInfo(alias).DeploymentID {
  fatalIf(errDummy().Trace(), fmt.Sprintf("License is invalid for the deployment %s", alias))
  }