software: Obsolete apache-frontend

software/caddy-frontend implements all requirements and apache-frontend is
not tested neither developed except small fixes, so it's ok to keep it for
reference or some small work outside of official tree, as other developers
might have urge to use it.
2 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed SlapOS.SlapRunner.ResilienceTest-Master

00:29:08

failed SlapOS.SlapRunner.ResilienceTest-Master.ERP5

01:57:35