2fc84e0fe3
According to the new dialog design, dialogs generally only have a title and a description, so the `body` property is no longer needed. At the places where it's still used, we replace it with the description property or a plain label we add to MessageDialogContent ourselves. See https://gitlab.gnome.org/GNOME/gnome-shell/issues/1343 https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/886