fix(DropdownField): fix array key value format

Author: stonebuzz

inc/field/dropdownfield.class.php

@@ -859,7 +859,7 @@ protected function getEntityRestriction() {
       switch ($restrictionPolicy) {
          case self::ENTITY_RESTRICT_FORM:
             $form = PluginFormcreatorForm::getByItem($this->getQuestion());
-            $formEntities = [$form->fields['entities_id']];
+            $formEntities = [$form->fields['entities_id'] => $form->fields['entities_id']];
             if ($form->fields['is_recursive']) {
                $formEntities = $formEntities + (new DBUtils())->getSonsof(Entity::getTable(), $form->fields['entities_id']);
             }
@@ -868,7 +868,7 @@ protected function getEntityRestriction() {
 
          case self::ENTITY_RESTRICT_BOTH:
             $form = PluginFormcreatorForm::getByItem($this->getQuestion());
-            $formEntities = [$form->fields['entities_id']];
+            $formEntities = [$form->fields['entities_id'] => $form->fields['entities_id']];
             if ($form->fields['is_recursive']) {
                $formEntities = $formEntities + (new DBUtils())->getSonsof(Entity::getTable(), $form->fields['entities_id']);
             }