[fix] interface language zh_CN and zh_TW don't work

Update translation branch according to commit 4759f65b6 in branch master::

    Before this commit, when the user picks "Chinese, China" or "Chinese,
    Taiwan", the locale fallbacks to English.

    This commit fixes this issue (the translations branch must be updated)

Related-to: https://github.com/searxng/searxng/pull/380

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>