udp punch and ipv6 punch

src/server.rs

@@ -246,7 +246,7 @@ pub async fn accept_connection(
     secure: bool,
 ) {
     if let Err(err) = accept_connection_(server, socket, secure).await {
-        log::error!("Failed to accept connection from {}: {}", peer_addr, err);
+        log::warn!("Failed to accept connection from {}: {}", peer_addr, err);
     }
 }