lib/util/charset: Remove autodetection of charset from LOCALE

lib/util/charset: Remove autodetection of charset from LOCALE

In the past, our LOCALE would set the display charset of Samba.  The
display charset has now been removed.  This patch removes the support
code that detected the locale from the environment.  We cannot safely
have 'unix charset' follow the locale (at it creates files on disk and
entries in databases that must not vary), so this code is unused.

As an example, imagine a database is manipulated in the
administrator's locale, and then read by smbd starting up in the
system default locale.  Or smbd restarted by the administrator rather
than a startup script.  Both of these situations could corrupt
databases or filenames on disk.

Andrew Bartlett