Revert "stunnel proxy protocol remote ip,port setting feature added for smtps."

This reverts commit eaebf766bca9e07d1aee8d9db18ad867de4f9643.
stunnel proxy protocol remote ip,port setting feature added for smtps.
reference : http://www.stunnel.org/static/stunnel.html
protocol spec : http://haproxy.1wt.eu/download/1.5/doc/proxy-protocol.txt