fix warnings

src/minecraft/client.rs

@@ -10,11 +10,9 @@
 /*                                                                            */
 /* ************************************************************************** */
 
-use async_std::task::sleep;
 use json::object;
 use tokio::net::TcpStream;
 use std::collections::VecDeque;
-use std::time::Duration;
 use crate::minecraft::handshake::Handshake;
 use crate::minecraft::varint::{varint_read, varint_write};
 use std::{fmt, io};