Disable apt authentication checks when building ubuntu-rtm images

against dogfood (that test archive is signed, but not with a very useful
key).

debian/changelog

@@ -1,3 +1,11 @@
+livecd-rootfs (2.226) UNRELEASED; urgency=medium
+
+  * Disable apt authentication checks when building ubuntu-rtm images
+    against dogfood (that test archive is signed, but not with a very useful
+    key).
+
+ -- Colin Watson <cjwatson@ubuntu.com>  Wed, 23 Jul 2014 01:48:35 +0100
+
 livecd-rootfs (2.225) utopic; urgency=medium
 
   * Use the soon-to-exist ubuntu-rtm archive for ubuntu-touch builds if

live-build/auto/config

@@ -344,6 +344,7 @@ case $PROJECT in
 		case $SUBPROJECT in
 		    ubuntu-rtm/dogfood)
 			MIRROR=http://derived-archive.dogfood.content.paddev.net/ubuntu-rtm/
+			OPTS="${OPTS:+$OPTS }--apt-secure false"
 			;;
 		    ubuntu-rtm)
 			MIRROR=http://derived.archive.canonical.com/ubuntu-rtm/