gpg: Avoid error diagnostics with --override-session-key when verifying
* src/engine-gpg.c (gpg_decrypt): only send --no-keyring when we are not verifying.
Without this change, the signature verification would fail. This
problem was introduced in bded8ebc59c7fdad2617f4c9232a58047656834c in
an attempt to avoid an error when *not* verifying. Clearly more test
suite coverage is needed to avoid introducing this sort of problem in
- GnuPG-bug-id: T3464
- Signed-off-by: Daniel Kahn Gillmor <firstname.lastname@example.org>