Warning under PHP8.x in printthread.php

[bv64]

on threads with multiple pages:

Warning [2] Undefined property: MyLanguage::$archive_pages - Line: 2 - File: printthread.php(287) : eval()'d code PHP 8.3.6 (Linux)

[Schnapsnase]

$lang->load("archive");

is missing in printthread.php

[bv64]

Template printthread_multipage contains two language variables, one is loaded, the other unnecessary

<div class="multipage">{$lang->pages} <strong>{$lang->archive_pages}</strong> {$mppage}</div>