Update download URLs
Commit ee733f9d (version up: zc.buildout 2.7.1+slapos017, slapos.libnetworkcache 0.23, 2022-03-28) introduced a new way of computing cache key used for shacache and downlaod URLs that were only in cache but no longer available from their original location no longer could be retrieved. This update the original download URLs to URLs that are valid today.