That is the new IP and port of the new server. This new server has slightly better hardware and is run by "reborn" of MP-Gaming.
To place this IP in your launcher program, select your profile and then go to the server listings. Press Add Server and a box will come up. Give the server any name you want in the "Server Name" box, then enter the IP (188.8.131.52) in the "Server IP" box, and then enter the Port (9999) in the "Server Port" box. You don't need a password. Press "ok" when done. (You may want to remove the old server first: Remove the server called "Official Server" by selecting "Official Server" and then remove server)