Add prepend_mod to PreferredLanguageSwitcher
requested to merge gitlab-jh/jh-team/gitlab:feat/add-prepend-mod-to-preferred-language-switcher into master
What does this MR do and why?
Add prepend_mod to PreferredLanguageSwitcher.
In JiHu, need to add additional conditions to the default language, so need to use prepend_mod.
Related MR in JiHu: https://jihulab.com/gitlab-cn/gitlab/-/merge_requests/1164
/cc JH EM @prajnamas