[Form] remove useless code in ResizeFormListener

Author: Tobion

Extension/Core/EventListener/ResizeFormListener.php

@@ -96,10 +96,6 @@ public function preSubmit(FormEvent $event)
         $form = $event->getForm();
         $data = $event->getData();
 
-        if (null === $data || '' === $data) {
-            $data = array();
-        }
-
         if (!is_array($data) && !($data instanceof \Traversable && $data instanceof \ArrayAccess)) {
             $data = array();
         }