Joomla 3 Use language label as title

//Set language label as title
// libraries/joomla/document/html/renderer/head.php
// line 115

$buffer .= $tab . '<title>' . htmlspecialchars($document->getTitle(), ENT_COMPAT, 'UTF-8') . '</title>' . $lnEnd;
//change into this
$buffer .= $tab . '<title>' . JTEXT::_(htmlspecialchars($document->getTitle(), ENT_COMPAT, 'UTF-8')) . '</title>' . $lnEnd;