Disable MP sync report generation by default.

A new Server.EnableSyncReports option is provided
so that server operators can restore them remotely
in the event of a future desync bug.

OpenRA.Game/Server/Server.cs

@@ -157,6 +157,7 @@ namespace OpenRA.Server
 					Map = settings.Map,
 					ServerName = settings.Name,
 					EnableSingleplayer = settings.EnableSingleplayer || !dedicated,
+					EnableSyncReports = settings.EnableSyncReports,
 					GameUid = Guid.NewGuid().ToString(),
 					Dedicated = dedicated
 				}