use ubuntu-unity-desktop metapackage for now

live-build/auto/config

@@ -824,7 +824,8 @@ case $PROJECT in
 		;;
 
 	ubuntu-unity)
-		add_task install minimal standard ubuntu-unity-desktop
+		add_task install minimal standard
+		add_package install ubuntu-unity # temporarily as seed is not up to date in universe
 		add_package live metacity ubiquity-frontend-gtk
 		add_package live ubiquity-ubuntu-artwork ubiquity-slideshow-ubuntu
 		add_package live a11y-profile-manager