bug#18258: t0251-gpt-unicode.sh fails when the C.UTF-8 locale is unavailable

[Ludovic Courtès]

Hello,

t0251-gpt-unicode.sh requires the C.UTF-8 locale and fails if it isn’t
available.

What about:

  1. Exiting with 77 when the locale is unavailable?

  2. Choosing another locale, such as en_US.utf8?  As of GNU libc 2.19,
     C.UTF-8 (or any other spelling) does not exist.

Thanks,
Ludo’.