[i18n] Updated Polish translation

[Jan Schneider]

Zitat von Maciej Uhlig <maciej.uhlig at us.edu.pl>:

> Please find some Polish translation updates for Horde's git version  
> at http://usnet.us.edu.pl/files/horde/horde_5_git_pl.zip .
>
> Previous translator has been notfied on the ongoing update.
>
> Thanks.
>
> MU

Committed, thanks.

-- 
Jan Schneider
The Horde Project
http://www.horde.org/
https://www.facebook.com/hordeproject