[FIX] tools: format_datetime with inactive lang
[FIX] tools: format_datetime with inactive lang

When selecting the lang browse record, it can be empty when language is not
activated. As we don't need that lang to be active to translate the
format datetime (lang code is enough for Bable lib), we simply
need to fallback to prevent error.
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo