Hmm, to make it better (and allow language dependent texts to be picked up correctly) you can make another change..
Change
// Assume they are not a moderator.
$user_info['is_mod'] = false;
$context['user']['is_mod'] = &$user_info['is_mod'];
// Start the linktree off empty..not quite, have to insert forum
$context['linktree'] = array(array('url' => $scripturl . '?action=forum', 'name' => isset($txt['tp-forum']) ? $txt['tp-forum'] : 'Forum'));
to
// Assume they are not a moderator.
$user_info['is_mod'] = false;
$context['user']['is_mod'] = &$user_info['is_mod'];
// load language file
if(loadLanguage('TPortal') == false) {
loadLanguage('TPortal', 'english');
}
// Start the linktree off empty..not quite, have to insert forum
$context['linktree'] = array(array('url' => $scripturl . '?action=forum', 'name' => isset($txt['tp-forum']) ? $txt['tp-forum'] : 'Forum'));