fix(bungee): 玩家传送至其他服务器时报错

hamster-ball-bungeecord/src/main/java/cn/hamster3/mc/plugin/core/bungee/listener/BallBungeeCordListener.java

@@ -98,6 +98,9 @@ public final class BallBungeeCordListener implements Listener, BallListener {
                 String serverID = event.getLocation().getServerID();
                 for (UUID uuid : event.getSendPlayerUUID()) {
                     ProxiedPlayer player = ProxyServer.getInstance().getPlayer(uuid);
+                    if (player == null) {
+                        continue;
+                    }
                     if (player.getServer().getInfo().getName().equals(serverID)) {
                         continue;
                     }