fix php 5.4 compatibility

library/ZendAfi/View/Helper/RenderLibrary.php

@@ -84,7 +84,8 @@ class ZendAfi_View_Helper_RenderLibrary extends ZendAfi_View_Helper_BaseHelper {
 
     $custom_field = $custom_fields[$custom_field_id];
 
-    if (empty($custom_field->getSelectedOptionsList()))
+    $selected_option = $custom_field->getSelectedOptionsList();
+    if (empty($selected_option))
       return $this->renderCustomField($custom_field, $custom_field_id);
 
     return $this->renderCustomFieldAsList($custom_field, $custom_field_id);