remove reference to pop3, telnet and rsh Makefiles
remove reference to pop3, telnet and rsh Makefiles

The pop3, telnet and rsh/rcp support was removed from the tree in
e55b0d0ca5038a8101276a593ffbb6be4c27c8d0. Delete the corresponding
Makefiles so autoconf doesn't try to look for them.

madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal