gpg: Allow setting notations with the empty string as value.
* g10/misc.c (pct_expando): Catch special case of the empty string. Also map a NULL to the empty string. * g10/photoid.c (show_photos): Make an empty string used as command fail.
This patch also fixes a segv when calling gpg wrongly like
gpg -N \-foo@example.org
- GnuPG-bug-id: T5117
- Signed-off-by: Werner Koch <wk@gnupg.org>