Automatically link the superuser account to federated service for auth

When the user commits the configuration, if they have chosen a non-DB auth system, we now auto-link the superuser account to that auth system, to ensure they can login again after restart.

util/config/validator.py

@@ -344,7 +344,8 @@ def _validate_jwt(config, password):
   # Try to instatiate the JWT authentication mechanism. This will raise an exception if
   # the key cannot be found.
   users = ExternalJWTAuthN(verify_endpoint, issuer, OVERRIDE_CONFIG_DIRECTORY,
-                           app.config['HTTPCLIENT'])
+                           app.config['HTTPCLIENT'],
+                           app.config.get('JWT_AUTH_MAX_FRESH_S', 300))
 
   # Verify that the superuser exists. If not, raise an exception.
   username = get_authenticated_user().username
@@ -403,4 +404,4 @@ _VALIDATORS = {
   'ldap': _validate_ldap,
   'jwt': _validate_jwt,
   'keystone': _validate_keystone,
-}
+}