fix proxy traffic not count into traffic (#1229)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

easytier/src/peers/peer_manager.rs

@@ -986,7 +986,19 @@ impl PeerManager {
     }
 
     pub async fn send_msg(&self, msg: ZCPacket, dst_peer_id: PeerId) -> Result<(), Error> {
-        Self::send_msg_internal(&self.peers, &self.foreign_network_client, msg, dst_peer_id).await
+        self.self_tx_counters
+            .self_tx_bytes
+            .add(msg.buf_len() as u64);
+        self.self_tx_counters.self_tx_packets.inc();
+        let msg_len = msg.buf_len() as u64;
+        let result =
+            Self::send_msg_internal(&self.peers, &self.foreign_network_client, msg, dst_peer_id)
+                .await;
+        if result.is_ok() {
+            self.self_tx_counters.self_tx_bytes.add(msg_len);
+            self.self_tx_counters.self_tx_packets.inc();
+        }
+        result
     }
 
     async fn send_msg_internal(