LDAP error Class 'humhub\modules\user\libs\LdapException' not found when using wrong password

[pirobase-pfuchs]

When trying to log on to HumHub 1.0 using LDAP authentication and wrong credentials a PHP error screen is displayed saying that class 'humhub\modules\user\libs\LdapException' could not be found:

PHP Fatal Error – yii\base\ErrorException

Class 'humhub\modules\user\libs\LdapException' not found

1. in /var/www/humhub-1.0.0/protected/humhub/modules/user/libs/Ldap.php at line 113

        // disconnect id needed here because otherwise binding/ldap connection again can cause errors.
        $this->ldap->disconnect();

        // Update Users Data
        $node = $this->ldap->getNode($username);
        $this->handleLdapUser($node);
        return true;
    } catch (\Zend\Ldap\Exception\LdapException $ex) {
        // log errors other than invalid credentials
        if ($ex->getCode() !== LdapException::LDAP_INVALID_CREDENTIALS) {
            Yii::error('LDAP Error: ' . $ex->getMessage());
        }
        return false;
    } catch (Exception $ex) {
        Yii::error('LDAP Error: ' . $ex->getMessage());
        return false;
    }
}

Instead a rendered error message should be displayed.