Fix memory leak

src/de/steamwar/misslewars/FightScoreboard.java

@@ -25,6 +25,7 @@ import org.bukkit.Bukkit;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
 import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.event.player.PlayerQuitEvent;
 import org.bukkit.scoreboard.DisplaySlot;
 import org.bukkit.scoreboard.Objective;
 import org.bukkit.scoreboard.Scoreboard;
@@ -78,6 +79,11 @@ class FightScoreboard implements Listener {
         });
     }
 
+    @EventHandler
+    public void onPlayerQuit(PlayerQuitEvent event) {
+        SWScoreboard.removeScoreboard(event.getPlayer());
+    }
+
     static Scoreboard getScoreboard() {
         return scoreboard;
     }