[plg_system_logout] Load language files only when needed (joomla#11736)

* Update logout.php

* cs and stuff

* Update logout.php

plugins/system/logout/logout.php

@@ -16,14 +16,6 @@
  */
 class PlgSystemLogout extends JPlugin
 {
-	/**
-	 * Load the language file on instantiation.
-	 *
-	 * @var    boolean
-	 * @since  3.1
-	 */
-	protected $autoloadLanguage = true;
-
 	/**
 	 * Constructor.
 	 *
@@ -82,23 +74,26 @@ public function onUserLogout($user, $options = array())
 	/**
 	 * Method to handle an error condition.
 	 *
-	 * @param   Exception  &$error  The Exception object to be handled.
+	 * @param   Exception  $error  The Exception object to be handled.
 	 *
 	 * @return  void
 	 *
 	 * @since   1.6
 	 */
-	public static function handleError(&$error)
+	public static function handleError($error)
 	{
 		// Get the application object.
 		$app = JFactory::getApplication();
 
 		// Make sure the error is a 403 and we are in the frontend.
-		if ($error->getCode() == 403 and $app->isSite())
+		if ($error->getCode() == 403 && $app->isSite())
 		{
+			// Load language file.
+			parent::loadLanguage();
+
 			// Redirect to the home page.
-			$app->enqueueMessage(JText::_('PLG_SYSTEM_LOGOUT_REDIRECT'));
-			$app->redirect('index.php');
+			$app->enqueueMessage(JText::_('PLG_SYSTEM_LOGOUT_REDIRECT'), 'message');
+			$app->redirect(JRoute::_('index.php'));
 		}
 		else
 		{