I'm getting a fatal error if external url is selected and we leave the custom text field empty.

[01-Nov-2018 10:55:40 UTC] PHP Fatal error: Method Craft\FruitLinkIt_LinkModel::__toString() must not throw an exception, caught CException: Craft\FruitLinkIt_LinkModel en zijn behaviors hebben geen method of closure met naam "getThirdPartyElementData". in /common/craft/app/vendor/twig/twig/lib/Twig/Extension/Core.php on line 0