Fix NPE

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

BauSystem_Main/src/de/steamwar/bausystem/features/simulator/SimulatorPreviewStorage.java

@@ -79,7 +79,7 @@ public class SimulatorPreviewStorage {
 
     public void recalculate(TNTSimulator tntSimulator) {
         Pair<Record, Set<Player>> pair = previews.get(tntSimulator);
-        if (previews == null) return;
+        if (pair == null) return;
         pair.setKey(SimulatorPreview.impl.simulate(tntSimulator));
         pair.getValue().forEach(player -> {
             Pair<TNTSimulator, ShowMode<TNTPosition>> setPair = showModes.get(player);