tests/openpgp: Make tests more portable.
* tests/openpgp/default-key.test: Avoid 'grep -q'. * tests/openpgp/gpgtar.test: Avoid 'grep -qe' and 'diff -q'. * tests/openpgp/use-exact-key.test: Avoid 'grep -q'.
- GnuPG-bug-id: T2262
- Signed-off-by: Justus Winter <justus@g10code.com>