fix compile failure

OpenRA.Game/Traits/SubcellInit.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using OpenRA.FileFormats;
+
+namespace OpenRA.Traits
+{
+	public class SubCellInit : IActorInit<SubCell>
+	{
+		[FieldFromYamlKey]
+		public readonly int value = 0;
+
+		public SubCellInit() { }
+
+		public SubCellInit(int init)
+		{
+			value = init;
+		}
+
+		public SubCell Value(World world)
+		{
+			return (SubCell)value;
+		}
+	}
+}