AppVeyor: simplify preparation for debugging
AppVeyor: simplify preparation for debugging

rgrinberg/lwt,rgrinberg/lwt,c-cube/lwt,ocsigen/lwt,c-cube/lwt,rgrinberg/lwt,rneswold/lwt,rneswold/lwt,ocsigen/lwt,ocsigen/lwt,c-cube/lwt,rneswold/lwt,rgrinberg/lwt