If browser gives ru (not ru-RU) the default language is used

[ekDanilova]

Hi! Hope someone may help me, please. I have a very simple one-page website.
I connected this library: used your l10n.js, added locales.ini with:
[*] @import url(data.en.properties) [ru] @import url(data.ru.properties)`

and two files data.en.properties and data.ru.properties.

The situation is that If navigator.language is [ru-RU] it is translated as [ru]. And it's great! English works fine too.
But, if navigator.language is [ru] it uses the default language, which is [en].
Absolutely don't know what's wrong :(
Dream of some help...