Preserve initial readiness while sender waits for a session

src/transport_layer/etcp.c

@@ -1234,7 +1234,7 @@ struct ETCP_DGRAM* etcp_request_pkt(struct ETCP_CONN* etcp) {
     if (!etcp) return NULL;
     if (etcp->state == 2) { DEBUG_WARN(DEBUG_CATEGORY_ETCP, "[%s] request_pkt on deleted conn", etcp->log_name); return NULL; }
     if (etcp->close_requested || !etcp->initialized || etcp->session_required || etcp->reinit_pending) {
-        etcp->tx_state = ETCP_TX_STATE_LINK_WAIT;
+        if (etcp->tx_state) etcp->tx_state = ETCP_TX_STATE_LINK_WAIT;
         return NULL;
     }
     if (!etcp->input_send_q->head) input_queue_try_push(etcp);