fix(readme): simplify add tenant ext user

Author: snowch

README.md

@@ -116,7 +116,7 @@ hpecp tenant examples
 Add LDAP role to Tenant:
 ```sh
 ADMIN_GROUP="CN=DemoTenantAdmins,CN=Users,DC=samdom,DC=example,DC=com"
-ADMIN_ROLE=$(hpecp role list  --query "[?label.name == 'Admin'][_links.self.href] | [0][0]" --output json | tr -d '"')
+ADMIN_ROLE=$(hpecp role list  --query "[?label.name == 'Admin'][_links.self.href]" --output text)
 hpecp tenant add-external-user-group --tenant-id $TENANT_ID --group $ADMIN_GROUP --role-id $ADMIN_ROLE
 ```