FD3-684 fix filter onu

src/FTTHBundle/Admin/ONUAdmin.php

@@ -42,6 +42,8 @@ class ONUAdmin extends WorkflowBaseAdmin
                                     {$alias}.ponSerialNumber LIKE :id OR 
                                     {$alias}.ponSerialNumberAux LIKE :id")
                         ->setParameter('id', "%{$data['value']}%");
+                        
+                    return true;
                 },), null, [
                     'attr' => [
                         'placeholder' => $this->trans('sonata.filter.onu_id')