How to narrow list of languages?

[Kiss Gabor (Bitman)]

I've installed a live lubuntu onto a USB stick.
I wanted to switch language to Hungarian on login screen of lxdm
but accidentally I selected Belorusian.
Now it is added to language menu and I found no way to remove it.
I checked all files of persistent data stored in /casper-rw disk image
but I found no "be_BY" string. Nor filename containig these chars.

How could I restore the original state?

Thanks

Gabor
-- 
Wenn ist das Nunstück git und Slotermeyer?
Ja! ... Beiherhund das Oder die Flipperwaldt gersput.