Switch to OpenSpy master server for Unreal Tournament 2004 (GameServerManagers#133)

* fix(ut2k4): Remove GameSpy master servers

* feat(ut2k4): Use OpenSpy master instead of soon defunct Epic master
closes GameServerManagers/LinuxGSM#4086

Author: cetteup

UnrealTournament2004/UT2004.ini

@@ -269,11 +269,7 @@ ServerBehindNAT=False
 [IpDrv.MasterServerLink]
 LANPort=11777
 LANServerPort=10777
-MasterServerList=(Address="ut2004master1.epicgames.com",Port=28902)
-MasterServerList=(Address="ut2004master2.epicgames.com",Port=28902)
-MasterServerList=(Address="master.333networks.com",Port=27900)
-MasterServerList=(Address="master.errorist.tk",Port=27900)
-MasterServerList=(Address="master.newbiesplayground.net",Port=27900)
+MasterServerList=(Address="utmaster.openspy.net",Port=28902)
 
 [IpDrv.HTTPDownload]
 RedirectToURL=