setsockopt arg optvalue supposed to be ptr

vlib/net/socket.v

@@ -65,7 +65,7 @@ pub fn socket(family int, _type int, proto int) Socket {
 }
 
 // set socket options
-pub fn (s Socket) setsockopt(level int, optname int, optvalue int) int {
+pub fn (s Socket) setsockopt(level int, optname int, optvalue *int) int {
 	res := C.setsockopt(s.sockfd, level, optname, optvalue, C.sizeof(optvalue))
 	return res
 }