Delete previous generated nav file on success.
Delete previous generated nav file on success.

If we have successfully written and renamed the new nav file, we don't
need the old one anymore.
If you still want to retreive the previous
file, there is a daily backup done by the DevOps team that can recover
the file on demand.

CanalTP/navitia,xlqian/navitia,Tisseo/navitia,Tisseo/navitia,CanalTP/navitia,CanalTP/navitia,xlqian/navitia,Tisseo/navitia,xlqian/navitia,Tisseo/navitia,CanalTP/navitia,xlqian/navitia,xlqian/navitia,CanalTP/navitia,Tisseo/navitia