Only include languages which either:

* Have a PO file in tails.git
* Are on our list of tier 1 supported languages:

    Arabic - AR
    German - DE
    English - EN
    Spanish - ES
    Farsi - FA
    French - FR
    Hindi
    Indonesian
    Italian - IT
    Portuguese - PT-BR
    Russian - RU
    Turkish - TR
    Simplified Chinese - zh-CN