qt: Use --quick-set-ownertrust if available
* lang/qt/src/qgpgmechangeownertrustjob.cpp (set_owner_trust): New. (QGpgMEChangeOwnerTrustJob::start): Use set_owner_trust if gpg is new enough. * lang/qt/tests/t-ownertrust.cpp (ChangeOwnerTrustTest::testChangeOwnerTrust): Log unexpected error.
Using the --quick-set-ownertrust command to set the owner trust is much
more robust than using the edit interface. Prefer the former if gpg
supports it.
- GnuPG-bug-id: T7239