Minor improvement of auto-update check
Minor improvement of auto-update check

Instead of relying on /etc/apt/apt.conf.d/20auto-upgrades having the
according entries we now verify the auto-upgrade entries via apt-config

jvalleroy/plinth-debian,harry-7/Plinth,freedomboxtwh/Plinth,vignanl/Plinth,kkampardi/Plinth,kkampardi/Plinth,jvalleroy/plinth-debian,vignanl/Plinth,kkampardi/Plinth,harry-7/Plinth,jvalleroy/plinth-debian,vignanl/Plinth,freedomboxtwh/Plinth,kkampardi/Plinth,kkampardi/Plinth,freedomboxtwh/Plinth,jvalleroy/plinth-debian,harry-7/Plinth,freedomboxtwh/Plinth,harry-7/Plinth,jvalleroy/plinth-debian,freedomboxtwh/Plinth,vignanl/Plinth,vignanl/Plinth,harry-7/Plinth