This re-adds the missing setlocale( LC_NUMERIC, "C" ); that was
not transferred when ntdll locale code was moved to ntdll/unix in
commit b86dc3926bfe5cd92400aa96c89b0255eba1d447.

Fixes:
https://bugs.winehq.org/show_bug.cgi?id=49489
https://bugs.winehq.org/show_bug.cgi?id=49417