region: don't crash for locales with no country_code

gnome_parse_locale() can return an empty country_code for some locales,
which we are not taking into account when building the simple_locale
string.

[endlessm/eos-shell#4017]
Tabs to spaces

[endlessm/eos-shell#4017]
Merge pull request #24 from endlessm/shell/4017

region: don't crash for locales with no country_code
Arabic translations from Transifex

[endlessm/eos-shell#4032]