Allow local account login with local login disabled.

The configuration option "Which users should be allowed to login with local accounts?" don't work if the local login is enable.

I think we need to add on SimplesamlSubscriber.php:79:

    if ($this->account->isAuthenticated()) {
      $allowed_uids = explode(',', $this->config->get('allow.default_login_users'));
      if (in_array($this->account->id(), $allowed_uids)) {
        return;
      }
    }

In order to allow some user to login event though local login is disable.