This is a fixup to the previous patch, which adds the patches to
gnu/local.mk.

Unfortunately, the message I've sent along with the previous patch went
missing, so I'm trying to reconstruct it here:
"This patch fixes the currently broken Seahorse build. Seahorse has
switched to the Meson build system upstream, so this change is
reflected in the package and inputs were adjusted. Two upstream patches
are also applied, one of them with adjusted offset."