openpgp: Fix SignatureBuilder::signature_expiration_time.
-
SignatureBuilder::signature_expiration_time is broken. This is because SignatureBuilder doesn't actually implement signature_expiration_time. Instead, it is resolved via a Deref to the SubpacketAreas::signature_expiration_time. That function returns: creation_time subpacket + expiration_time subpacket, but the actual creation time in a SignatureBuilder may not yet have propagated to the subpacket area!
- Fixes #998 (closed).