Add the auth-server-proxy (separate Debian pkg)

The proxy allows us to reduce SSL connection overhead to a remote
server by multiplexing proxied requests from the local UNIX socket.
2 jobs for tcp in 1 minute and 40 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build Pkgsrc
passed #21139
build_pkgsrc:buster

00:00:29

 
  Build Pkg
passed #21140
amd64
build_pkg:buster:amd64

00:01:10