Remove unused imports

src/udp.rs

@@ -1,5 +1,5 @@
 use std::collections::HashMap;
-use std::sync::atomic::{AtomicI32, AtomicU64};
+use std::sync::atomic::AtomicI32;
 use std::sync::Arc;
 
 use log::{debug, error, info, trace};
@@ -7,7 +7,6 @@ use rand::seq::SliceRandom;
 
 use tokio::net::UdpSocket;
 use tokio::sync::Mutex;
-use tokio::time::Instant;
 
 use crate::listener::Listener;
 use crate::shutdown::{Shutdown, ShutdownReceiver};