Enable universe in sources.list for IMAGEFORMAT=none

debian/changelog

@@ -1,3 +1,10 @@
+livecd-rootfs (2.598) UNRELEASED; urgency=medium
+
+  * Enable universe in sources.list for IMAGEFORMAT=none, which is used for
+    our preinstalled ubuntu-image rootfs builds.
+
+ -- Łukasz 'sil2100' Zemczak <lukasz.zemczak@ubuntu.com>  Mon, 24 Jun 2019 16:16:34 +0200
+
 livecd-rootfs (2.597) eoan; urgency=medium
 
   * Install s390-tools-zkey into the installer layer for zkey support in

live-build/auto/config

@@ -402,6 +402,10 @@ case $IMAGEFORMAT in
 
 	none)
 		OPTS="${OPTS:+$OPTS }--chroot-filesystem $IMAGEFORMAT"
+		# IMAGEFORMAT=none is used for our ubuntu-image preinstalled
+		# image rootfs builds.  Make sure the sources.list has universe
+		# enabled for those images as well.
+		touch config/universe-enabled
 		;;
 	*)
 		case $PROJECT in