Prevent dunst from autostarting using DBus

By default, dunst is autostarted by DBus. This can be turned off by editing /usr/share/dbus-1/services/org.knopwob.dunst.service and changing

Exec=/usr/bin/dunst

To:

Exec=/usr/bin/true

Source:
https://lists.archlinux.org/pipermail/arch-general/2015-January/038282.html