Solved Removing unknown command message

How can I remove the message "Unknown comand. Type "help" for help" when i use this code:

Code:

public void comando(PlayerCommandPreprocessEvent e){
String comando = e.getMessage().replace("/", "");
String nome = ChatColor.BLUE + "[RedSky] " + ChatColor.AQUA;
Player player = (Player) e.getPlayer();
if(plugin.getConfig().get("rportes." + comando) != null){
int x = plugin.getConfig().getInt("rportes."+ comando +".x"),y = plugin.getConfig().getInt("rportes."+ comando +".y"),z = plugin.getConfig().getInt("rportes."+ comando +".z");
 String mundos = plugin.getConfig().getString("rportes."+ comando +".mundo");
 World mundo = Bukkit.getWorld(mundos);
 player.teleport(new Location(mundo, x, y, z));
 player.sendMessage(nome + "Ok! Good game");
}
}

The code is working, but when used give me that error .-.

 

Cancel the event.
Like this

Code:

e.setCancelled(true);

 

Tog Thanks ;D