Massage our crummy REINPLACE to also accept the current version
of gnupg that is in ports, so this can build agani. While here,
fix the pkg-descr which was still a copy of seahorse (from which
this package was split several years ago).
Upstream has marked this as "likely to be deprecated", and there
has been no release in 4 years. There *has* been an upstream
commit doing what our REINPLACE does, up to gnupg 2.2.