Drop file-rc support file-rc used to be the init system up and until including Grml stable release 2014.11, starting with beginning of 2016 Grml switched to systemd instead. The last Debian release that used to have file-rc available was Debian/stretch, which is EOL and we don't support it neither anymore. So, good riddance!
Update FILE_RC + systemd classes for aptitude->apt switch
Systemd support, providing backwards compatibility via FILE_RC class [Closes: issue1015] Support for file-rc is still available and can be enabled via FILE_RC class.