tests: Fix using tools from the build directory.
* tests/openpgp/defs.scm (gpg-conf'): Explicitly pass the build prefix to gpgconf here... (gpg-components): ... instead of only here.
Previously, gpgconf was not invoked with '--build-prefix' when
changing the configuration. This made tests using this facility fail
(e.g. the TOFU test). This only affected release builds, because in
development builds gpgconf picks up the build prefix from the
- GnuPG-bug-id: T2979
- Signed-off-by: Justus Winter <email@example.com>