Update plupload.php

Не все переведено. :(
Update plupload.php
Remove unused language string.

https://github.com/phpbb/phpbb/commit/628323a80af58642565ff55f381e7b289f45b8da
Update plupload.php
Update plupload.php
Merge branch 'patch-26' of git://github.com/sherl0ck044/Olympusrupack into sherl0ck044-patch-26