Fix create empty translation page

When clicking _"Create as an empty page"_ I get the following exception:
```
ContextErrorException: Catchable Fatal Error: 
Argument 4 passed to Kunstmaan\NodeBundle\Event\NodeEvent::__construct() must implement 
interface Kunstmaan\NodeBundle\Entity\HasNodeInterface, string given, called in vendor/kunstmaan
/node-bundle/Kunstmaan/NodeBundle/Controller/NodeAdminController.php on line 167 and defined in 
vendor/kunstmaan/node-bundle/Kunstmaan/NodeBundle/Event/NodeEvent.php line 49
```