fixed lang does not work

[katsuren]

setting lang attribute doesn't work in my project. PHP 7.2

It cannot execute method within "{}"

<?php

$lang = 'jpn';
$tag = "<LANG>{strtoupper($lang)}</LANG>";
echo $tag;

// it shows
//  <LANG>{strtoupper(jpn)}</LANG>

[jpmurray]

I'm sorry this has been under the radar, I never got any notifications from Github about pull requests, so I kind of never saw them! This is embarrassing!

I'll be merging them in master the coming days.