Fix Bau delmember when player online but Bau not running

Signed-off-by: Lixfel <git-5w3l@lixfel.de>

src/de/steamwar/velocitycore/commands/BauCommand.java

@@ -162,7 +162,8 @@ public class BauCommand extends SWCommand {
             Chatter member = Chatter.of(user.getUUID());
             member.system("BAU_DELMEMBER_DELETED_TARGET", owner);
             member.withPlayer(player -> {
-                if (Bauserver.get(owner.user().getUUID()).getRegisteredServer().getPlayersConnected().contains(player))
+                Bauserver bauserver = Bauserver.get(owner.user().getUUID());
+                if (bauserver != null && bauserver.getRegisteredServer().getPlayersConnected().contains(player))
                     player.createConnectionRequest(VelocityCore.get().getConfig().lobbyserver()).fireAndForget();
             });