Refresh RTO before RTT callbacks can close the link

src/transport_layer/etcp.c

@@ -1466,14 +1466,14 @@ void etcp_conn_input(struct ETCP_DGRAM* pkt) {
                 etcp->rtt_avg_10=rtt_max;
                 etcp->tt_last=tt_sum/cnt;
                 etcp->jitter=j_sum/cnt;
-                if (etcp->rtt_last) {
+                if (new_rtt != prev_rtt) etcp_tx_update_rto(pkt->link);
+                if (!etcp->close_requested && etcp->rtt_last) {
                     uint64_t now_tb = get_time_tb();
                     if (now_tb - etcp->last_rtt_cb_time > RTT_CB_PERIOD_TB) {
                         topo_node_ping_update_rtt(etcp->instance->topo_groups, etcp->peer_node_id, etcp->rtt_last);
                         etcp->last_rtt_cb_time = now_tb;
                     }
                 }
-                if (new_rtt != prev_rtt) etcp_tx_update_rto(pkt->link);
                 break;
             }
             case ETCP_SECTION_PAYLOAD: {