fix custom field wich could not be saved

src/Bundle/ChillCustomFieldsBundle/Form/Type/ChoiceWithOtherType.php

@@ -22,13 +22,12 @@ class ChoiceWithOtherType extends AbstractType
      */
     public function buildForm(FormBuilderInterface $builder, array $options)
     {
-
         //add an 'other' entry in choices array
         $options['choices'][$this->otherValueLabel] = '_other';
         //ChoiceWithOther must always be expanded
         $options['expanded'] = true;
         // adding a default value for choice
-        $options['empty_data'] = null;
+        $options['empty_data'] = $options['multiple'] ? [] : null;
 
         $builder
             ->add('_other', TextType::class, array('required' => false))