Fix editor compilation.

OpenRA.Editor/MapSelect.cs

@@ -45,7 +45,7 @@ namespace OpenRA.Editor
 			if (DirectoryIsEmpty(MapFolderPath))
 				return;
 
-			foreach (var map in ModData.FindMapsIn(MapFolderPath))
+			foreach (var map in MapCache.FindMapsIn(MapFolderPath))
 			{
 				ListViewItem map1 = new ListViewItem();
 				map1.Tag = map;

OpenRA.Game/MapCache.cs

@@ -57,7 +57,7 @@ namespace OpenRA
 			}
 		}
 
-		static IEnumerable<string> FindMapsIn(string dir)
+		public static IEnumerable<string> FindMapsIn(string dir)
 		{
 			string[] noMaps = { };