gpg: Re-group the options in the --help output.

* g10/gpg.c (opts): Change oLoadExtensions, oStrict, and oNoStrict to
use ARGPARSE_ignore and remove the code in the option switch.

This looks better and is also required for further simplifications of
gpgconf.

(cherry picked from commit 41eb5108ce59244d961df43bbf73b8aa6e95e9cd)

• Signed-off-by: Werner Koch <wk@gnupg.org>