Merge branch 'hi/gpg-optional-pkfp-fix'

The code to parse GPG output used to assume incorrectly that the finterprint for the primary key would always be present for a valid signature, which has been corrected. * hi/gpg-optional-pkfp-fix: gpg-interface: limit search for primary key fingerprint gpg-interface: refactor the free-and-xmemdupz pattern