Set dark wallpaper when setting wallpaper too

Jeremy Bicha requested to merge jbicha/nautilus:dark-background-master into master

This change only has an affect when nautilus is built without the libportal option

This matches the current behavior of xdg-desktop-portal-gnome

xdg-desktop-portal-gnome@84f4f861

The merge proposal for the GNOME 42 branch is !806 (merged)

Merge request reports