Ask for a new seqno when a route is about to expire.

babel.c

@@ -758,7 +758,7 @@ expire_routes(void)
         if(route->installed && route->refmetric < INFINITY) {
             if(route->time < now.tv_sec - MAX(5, route_timeout_delay - 25))
                 send_unicast_request(route->nexthop, route->dest,
-                                     max_request_hopcount, route->dest->seqno);
+                                     max_request_hopcount, -1);
         }
         i++;
     }