allow mod override

e.g. useful for legacy maps where RequiresMod: is not set

OpenRA.Utility/Command.cs

@@ -297,8 +297,8 @@ namespace OpenRA.Utility
 		public static void GenerateMinimap(string[] args)
 		{
 			var map = new Map(args[1]);
-
-			Game.modData = new ModData(map.RequiresMod);
+			var mod = args.Length > 1 ? args[2] : map.RequiresMod;
+			Game.modData = new ModData(mod);
 
 			FileSystem.UnmountAll();
 			foreach (var dir in Game.modData.Manifest.Folders)