fix(UserAttribute) Reset blacklist and whitlist to avoid problems

issue #5816

include/simpleplugin/class_dialogAttributes.inc

@@ -102,6 +102,13 @@ class SingleUserSelectDialog extends GenericDialog
 {
   protected $dialogClass = 'singleUserSelect';
 
+  function dialog_execute ()
+  {
+    session::set('filterBlacklist', $this->attribute->getFilterBlackList());
+    session::set('filterWhitelist', $this->attribute->getFilterWhiteList());
+    return parent::dialog_execute();
+  }
+
   function handle_finish ()
   {
     $result = $this->dialog->detectPostActions();
@@ -706,6 +713,16 @@ class DialogButtonAttribute extends ButtonAttribute
       $this->plugin->openDialog(new $this->dialogClass($this->plugin, $this));
     }
   }
+
+  function getFilterBlackList ()
+  {
+    return array();
+  }
+
+  function getFilterWhiteList ()
+  {
+    return array();
+  }
 }
 
 /*!