Enforce using UTF-8
    
    In python3 locale.normalize('en') returns 'en_US.ISO8859-1' but we prefer
    to default to UTF-8, so if there is a '.' in the local return, just
    ignore what is after it and force using UTF-8.
    
    Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>