Potential Border rejoin fix

Signed-off-by: Lixfel <agga-games@gmx.de>

FightSystem_Core/src/de/steamwar/fightsystem/fight/FightTeam.java

@@ -201,13 +201,16 @@ public class FightTeam {
         schematic.reset();
 
         Set<UUID> playerSet = new HashSet<>(players.keySet());
-        for(UUID uuid : playerSet){
+        playerSet.removeIf(uuid -> {
             Player player = Bukkit.getPlayer(uuid);
-            if(player == null)
+            if(player == null || !player.isOnline()) {
                 removePlayer(players.get(uuid).getEntity());
+                return true;
             }
+
+            return false;
+        });
         FightPlayer leaderBackup = leader;
-        playerSet.removeIf(uuid -> Bukkit.getPlayer(uuid) == null);
         players.clear();
         leader = null;
 

FightSystem_Core/src/de/steamwar/fightsystem/listener/Border.java

@@ -61,7 +61,7 @@ public class Border {
     }
 
     public void addPlayer(Player player) {
-        if(ghostBarriers.containsKey(player))
+        if(ghostBarriers.containsKey(player) || !player.isOnline())
             return;
 
         ghostBarriers.put(player, new HashSet<>());