fix ui issue when deleting a one-to-X element

Controller/HelperController.php

@@ -180,8 +180,8 @@ class HelperController
 
         $object = $admin->getObject($objectId);
 
-        if (!$object) {
-            throw new NotFoundHttpException();
+        if (!$object && 'html' == $request->get('_format')) {
+            return new Response();
         }
 
         if ('json' == $request->get('_format')) {

Resources/views/Helper/short-object-description.html.twig

@@ -1,5 +1,5 @@
 <span class="inner-field-short-description">
-    {% if admin.hasRoute('edit') and admin.isGranted('EDIT') %}
+    {% if object and admin.hasRoute('edit') and admin.isGranted('EDIT') %}
         <a href="{{ admin.generateObjectUrl('edit', object) }}" target="new">{{ description }}</a>
     {% else %}
         {{ description }}