Fix Debian Live boot to use the debian cdarchive

Stretch currently does not build images at this time

src/livedebian.ipxe

@@ -9,7 +9,7 @@ goto ${menu}
 set os Debian Live
 menu ${os}
 item --gap Versions
-item 8.8.0 ${space} ${os} 8.8.0
+item 8.9.0 ${space} ${os} 8.9.0
 choose livedebian_version || goto livedebian_exit
 
 :livedebian_flavor
@@ -27,8 +27,8 @@ echo ${cls}
 goto livedebian_boot
 
 :livedebian_boot
-set webboot_host mirrors.kernel.org
-set livedebian_url http://${webboot_host}/debian-cd/${livedebian_version}-live/amd64/webboot/debian-live-${livedebian_version}-amd64-${flavor}-desktop
+set webboot_host cdimage.debian.org
+set livedebian_url http://${webboot_host}/cdimage/archive/${livedebian_version}-live/amd64/webboot/debian-live-${livedebian_version}-amd64-${flavor}-desktop
 imgfree
 kernel ${livedebian_url}.vmlinuz boot=live config hooks=filesystem username=live noeject ${console} fetch=${livedebian_url}.squashfs initrd=debian-live-${livedebian_version}-amd64-${flavor}-desktop.initrd.img
 module ${livedebian_url}.initrd.img