need help changing default site language

[Alb]

Hello. I need some help with changing the frontend default language of the site. I a using the I18N plugin to make my site in 4 diferent languages.

PHP Code:

sq_AL
en_US
it_IT
ro_RO 


I am trying to make the default language of the site from en_US in sq_AL . I tried to add

PHP Code:

$LANG = "sq_AL"; 


in gsconfig but it wasn't working.
Some help?
Thanks in advance