Preserve cold NAT trials in the real network fixture

src/routing_layer/nat_detection.c

@@ -1367,6 +1367,7 @@ void nat_detection_connection_failed(struct NAT_DETECTION *detector, struct ETCP
             struct ll_entry *packet = ll_alloc_lldgram(1 + sizeof(request));
             if (!packet) { DEBUG_ERROR(DEBUG_CATEGORY_NAT, "NAT failure recheck allocation failed"); break; }
             packet->dgram[0] = ETCP_RT_ID_NAT_DETECTION; memcpy(packet->dgram + 1, &request, sizeof(request));
+            packet->len = 1 + sizeof(request);
             if (etcp_route_send(detector->instance, group->group_id, connection->peer_node_id, packet, 0,
                                 ROUTE_CRYPTO_SIGN | ROUTE_CRYPTO_ENCRYPT))
                 DEBUG_WARN(DEBUG_CATEGORY_NAT, "NAT failure recheck forwarding failed group=%016llx peer=%016llx",