Qt loads only one specific file with QTranslate.load().
So if for example locale name is 'fr_CA', only this specific
translation will be loaded, but not 'fr', that may contains
usefull generic translations not given by lang_country one.

This patch fixes that by loading language code only fist
then 'language_COUNTRY' one.

Change-Id: I11a5adbd55f6575aab5453df0033377967ccc17e
Reviewed-by: Anthony Léonard <anthony.leonard@savoirfairelinux.com>