gnupg: enable the WKS server

Cristoph Lukas asked me why the WKS server was disabled, and I have
no idea. It was added r462573, and that commit message and associated
bug report don't list why --disable-wks-tools was added. (Folks,
please use commit messages for writing, you know, messages.)

We've been installing the gpg-wks-server manpage, so this commit
enables the WKS server and installs the binary, and bumps PORTREVISION
for it.

While here, sort the plist.