manifest: Drop dconf down to a known-working version
manifest: Drop dconf down to a known-working version

vrutkovs/vrutkovs.github.io,chergert/gnome-continuous,djdeath/gnome-ostree,chergert/gnome-continuous,GNOME/gnome-ostree,vrutkovs/vrutkovs.github.io,vrutkovs/vrutkovs.github.io,djdeath/gnome-ostree,djdeath/gnome-ostree,GNOME/gnome-ostree,chergert/gnome-continuous,GNOME/gnome-ostree