Dungeon: do not throw exceptions in stream operations (refactoring, S…

…pikeSystem)

see #1564 (comment)

dungeon/src/contrib/systems/SpikeSystem.java

@@ -20,6 +20,7 @@ public SpikeSystem() {
   @Override
   public void execute() {
     filteredEntityStream(SpikyComponent.class)
-        .forEach(e -> e.fetch(SpikyComponent.class).orElseThrow().reduceCoolDown());
+        .flatMap((e -> e.fetch(SpikyComponent.class).stream()))
+        .forEach(sc -> sc.reduceCoolDown());
   }
 }