server: increase listen queue to 128

This will allow more than 1 simultaneous client connections to the server
without the possibility of connection refused error.

Signed-off-by: Imran Zaman <imran.zaman@gmail.com>

http://utcc.utoronto.ca/~cks/space/blog/unix/ListenBacklogMeaning
http://stackoverflow.com/questions/19221105/connect-with-unix-domain-socket-and-full-backlog
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

src/wayland-server.c

@@ -1139,7 +1139,7 @@ _wl_display_add_socket(struct wl_display *display, struct wl_socket *s)
 		return -1;
 	}
 
-	if (listen(s->fd, 1) < 0) {
+	if (listen(s->fd, 128) < 0) {
 		wl_log("listen() failed with error: %m\n");
 		return -1;
 	}