Remove invalid caching from GCOT.

OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnTerrain.cs

@@ -35,9 +35,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		ConditionManager conditionManager;
 		int conditionToken = ConditionManager.InvalidConditionToken;
-
 		string cachedTerrain;
-		CPos cachedLocation;
 
 		public GrantConditionOnTerrain(ActorInitializer init, GrantConditionOnTerrainInfo info)
 		{
@@ -53,9 +51,10 @@ namespace OpenRA.Mods.Common.Traits
 		void ITick.Tick(Actor self)
 		{
 			var loc = self.Location;
-			if (conditionManager == null || loc == cachedLocation)
+			if (conditionManager == null)
 				return;
 
+			// The terrain type may change between ticks without the actor moving
 			var currentTerrain = loc.Layer == 0 ? self.World.Map.GetTerrainInfo(loc).Type :
 					tileSet[self.World.GetCustomMovementLayers()[loc.Layer].GetTerrainIndex(loc)].Type;
 
@@ -69,7 +68,6 @@ namespace OpenRA.Mods.Common.Traits
 			}
 
 			cachedTerrain = currentTerrain;
-			cachedLocation = loc;
 		}
 	}
 }