Fix AI giving orders to MCVs that already have orders

Checking for IsMoving is a flawed approach no matter how you look at it. The MCV might just have temporarily stopped due to an obstacle, or about to be deployed.

Checking for IsIdle instead ensures that the MCV really isn't already in the process of doing something.

OpenRA.Mods.Common/AI/HackyAI.cs

@@ -825,8 +825,7 @@ namespace OpenRA.Mods.Common.AI
 
 			foreach (var mcv in mcvs)
 			{
-				var mover = mcv.TraitOrDefault<IMove>();
-				if (mover != null && mover.IsMoving)
+				if (!mcv.IsIdle)
 					continue;
 
 				var factType = mcv.Info.TraitInfo<TransformsInfo>().IntoActor;