revert listen_failed_alert::port

include/libtorrent/alert_types.hpp

@@ -1292,9 +1292,6 @@ namespace libtorrent
 		// the specific low level operation that failed. See op_t.
 		int operation;
 
-		// the port attempted to be opened for listening
-		int port;
-
 		// the type of listen socket this alert refers to.
 		socket_type_t sock_type;
 

src/alert.cpp

@@ -804,7 +804,6 @@ namespace libtorrent {
 		, socket_type_t t)
 		: error(ec)
 		, operation(op)
-		, port(prt)
 		, sock_type(t)
 		, endpoint(parse_interface(iface, prt))
 		, m_alloc(alloc)