bugfix tcp disconnect

lib/relay.js

@@ -460,7 +460,7 @@ var Server = {
       try {
         srv.portsMap[portnumber].close(function () {
           console.log("[DynTcpConn] closing server for ", portnumber);
-          delete srv.portMap[portnumber];
+          delete srv.portsMap[portnumber];
           delete PortServers[portnumber];
         });
       } catch(e) { /*ignore*/ }