Update DepthCounterListener to count extension area as well

Signed-off-by: yoyosource <yoyosource@nidido.de>

BauSystem_Main/src/de/steamwar/bausystem/features/testblock/depthcounter/DepthCounterListener.java

@@ -42,7 +42,7 @@ public class DepthCounterListener implements Listener {
 			return;
 		}
 
-		DepthCounter.depthMap.computeIfAbsent(region, r -> new HashSet<>());
+		DepthCounter.depthMap.putIfAbsent(region, new HashSet<>());
 		Set<Depth> depthSet = DepthCounter.depthMap.get(region);
 		for (Depth depth : depthSet) {
 			if (depth.update(event.blockList())) {