Fix Leaderboard

src/de/steamwar/lobby/util/Leaderboard.java

@@ -31,6 +31,7 @@ public class Leaderboard implements Listener {
     private final Location location;
     private final int best;
     private long bestTime;
+    private final List<REntity> entities = new ArrayList<>();
     private final Map<Integer, REntityServer> playerPlacements = new HashMap<>();
 
     public Leaderboard(REntityServer server, String configKey, Location location, int best) {
@@ -43,7 +44,8 @@ public class Leaderboard implements Listener {
     }
 
     public void update() {
-        server.getEntities().forEach(REntity::die);
+        entities.forEach(REntity::die);
+        entities.clear();
         List<LeaderboardEntry> leaderboard = getLeaderboard();
         if (leaderboard.isEmpty()) return;
         bestTime = leaderboard.get(0).time;
@@ -59,6 +61,7 @@ public class Leaderboard implements Listener {
             }
             entity.setDisplayName(calcName(user, color, i + 1, entry.time));
             entity.setInvisible(true);
+            entities.add(entity);
         }
         Bukkit.getOnlinePlayers().forEach(player -> {
             updatePlayerPlacement(player, SteamwarUser.get(player.getUniqueId()));