Merge pull request #2032 from hxy7yx/v2.9-2

[v2.9]metric: reset send&recv bytes when restart node

src/connection/connection.c

@@ -125,7 +125,9 @@ void neu_conn_stop(neu_conn_t *conn)
 void neu_conn_start(neu_conn_t *conn)
 {
     pthread_mutex_lock(&conn->mtx);
-    conn->stop = false;
+    conn->state.recv_bytes = 0;
+    conn->state.send_bytes = 0;
+    conn->stop             = false;
     pthread_mutex_unlock(&conn->mtx);
 }