partially revert a5053e2d41e717 to fix mobile 2fa
partially revert a5053e2d41e717 to fix mobile 2fa

The status code change from 401 to 400 is not compatible with mobile
(yet). It will be after veloce/lichobile#910.

arex1337/lila,luanlv/lila,arex1337/lila,luanlv/lila,luanlv/lila,luanlv/lila,arex1337/lila,arex1337/lila,arex1337/lila,luanlv/lila,luanlv/lila,arex1337/lila,luanlv/lila,arex1337/lila