Fix race condition in ChillCollectionType

In some dcase, the collection is not initialized when a showHide is launched before the collection is fully initialized.

src/Bundle/ChillMainBundle/Form/Type/ChillCollectionType.php

@@ -36,6 +36,7 @@ class ChillCollectionType extends AbstractType
         $view->vars['identifier'] = $options['identifier'];
         $view->vars['empty_collection_explain'] = $options['empty_collection_explain'];
         $view->vars['js_caller'] = $options['js_caller'];
+        $view->vars['uniqid'] = uniqid();
     }
 
     public function configureOptions(OptionsResolver $resolver)