[FIX] tools: prevent crash of formatLang
[FIX] tools: prevent crash of formatLang

From Odoo 9.0, en_US is not always activated in Odoo. As a fallback, if
the search for a language does not find company language nor English US,
we use the first available language (there is always at least one).

In order to reproduce this behavior, eg: you can set the language of
your company's partner to en_US, then load another language, then
disable en_US from your database. Try to open the "Accounting" dashboard
and you will get a traceback.

ygol/odoo,dfang/odoo,hip-odoo/odoo,Elico-Corp/odoo_OCB,storm-computers/odoo,storm-computers/odoo,storm-computers/odoo,microcom/odoo,bplancher/odoo,microcom/odoo,storm-computers/odoo,ygol/odoo,dfang/odoo,bplancher/odoo,bplancher/odoo,ygol/odoo,hip-odoo/odoo,hip-odoo/odoo,laslabs/odoo,microcom/odoo,dfang/odoo,laslabs/odoo,Elico-Corp/odoo_OCB,dfang/odoo,Elico-Corp/odoo_OCB,Elico-Corp/odoo_OCB,bplancher/odoo,laslabs/odoo,hip-odoo/odoo,hip-odoo/odoo,ygol/odoo,microcom/odoo,storm-computers/odoo,microcom/odoo,dfang/odoo,bplancher/odoo,laslabs/odoo,dfang/odoo,Elico-Corp/odoo_OCB,microcom/odoo,Elico-Corp/odoo_OCB,storm-computers/odoo,bplancher/odoo,laslabs/odoo,laslabs/odoo,ygol/odoo,ygol/odoo,ygol/odoo,hip-odoo/odoo