Remove unused field from HandshakeRequest.

This field was not serialised, so compatibility
is not impacted.

OpenRA.Game/Network/Handshake.cs

@@ -18,7 +18,6 @@ namespace OpenRA.Network
 	{
 		public string Mod;
 		public string Version;
-		public string Map;
 		public string AuthToken;
 
 		public static HandshakeRequest Deserialize(string data)

OpenRA.Game/Server/Server.cs

@@ -289,7 +289,6 @@ namespace OpenRA.Server
 				{
 					Mod = ModData.Manifest.Id,
 					Version = ModData.Manifest.Metadata.Version,
-					Map = LobbyInfo.GlobalSettings.Map,
 					AuthToken = token
 				};