remove unused locale and request stack

The locale resolving is delegated to TranslatableStringHelper

CustomFields/CustomFieldChoice.php

@@ -45,12 +45,6 @@ class CustomFieldChoice extends AbstractCustomField
     const MULTIPLE = 'multiple';
     const EXPANDED = 'expanded';
     const CHOICES = 'choices';
-	
-    /**
-     * 
-     * @var RequestStack
-     */
-    private $requestStack;
 
     private $defaultLocales;
 
@@ -66,12 +60,10 @@ class CustomFieldChoice extends AbstractCustomField
     private $translatableStringHelper;
 	
     public function __construct(
-        RequestStack $requestStack, 
         Translator $translator, 
         TwigEngine $templating,
         TranslatableStringHelper $translatableStringHelper)
     {
-        $this->requestStack = $requestStack;
         $this->defaultLocales = $translator->getFallbackLocales();
         $this->templating = $templating;
         $this->translatableStringHelper = $translatableStringHelper;
@@ -80,7 +72,6 @@ class CustomFieldChoice extends AbstractCustomField
     public function buildForm(FormBuilderInterface $builder, CustomField $customField)
     {
         //prepare choices
-        $locale = $this->requestStack->getCurrentRequest()->getLocale();
         $choices = array();
         $customFieldOptions = $customField->getOptions();