Require a maintained version of libgcrypt.
* configure.ac: Require libgpg-error 1.25 and Libgcrypt 1.8 * src/util.h: Add missing error codes up to libgpg-error 1.27
Libgcrypt 1.7 reached EOL a year ago, thus we should not make such an
old version a requirement.
Libgpg-error was moderately updated to be in sync with the forthcoming
- GnuPG-bug-id: T4962
- Signed-off-by: Werner Koch <firstname.lastname@example.org>