fix deprecations: use fqcn fr translatable_string

CustomFields/CustomFieldChoice.php

@@ -32,6 +32,7 @@ use Symfony\Bridge\Twig\TwigEngine;
 use Chill\MainBundle\Templating\TranslatableStringHelper;
 use Symfony\Component\Translation\Translator;
 use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
+use Chill\MainBundle\Form\Type\TranslatableStringFormType;
 
 /**
  *
@@ -151,7 +152,7 @@ class CustomFieldChoice extends AbstractCustomField
                 'expanded' => true,
                 'multiple' => false
             ))
-            ->add(self::OTHER_VALUE_LABEL, 'translatable_string', array(
+            ->add(self::OTHER_VALUE_LABEL, TranslatableStringFormType::class, array(
                 'label' => 'Other value label (empty if use by default)'))
             ->add(self::CHOICES, new ChoicesType(), array(
                 'type' => new ChoicesListType($this->defaultLocales),