[PATCH COMMITTED] Chinese locales: Set first_weekday to 2 (bug 24682).

[Florian Weimer]

* Rafal Luzynski:

> I was going to push this patch just before 2.30 release but I forgot.
> OK to backport to 2.30 branch?  Carlos, anybody?

I think we rarely backport such changes, but it's still early in the
2.30 cycle, so it's probably okay.