[Merge] ~mwhudson/livecd-rootfs/+git/livecd-rootfs:fix-canary-build into livecd-rootfs:ubuntu/master

[Michael Hudson-Doyle]

Self approving this now I've tested it works.
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https://code.launchpad.net/~mwhudson/livecd-rootfs/+git/livecd-rootfs/+merge/446003
Your team Ubuntu Core Development Team is requested to review the proposed merge of ~mwhudson/livecd-rootfs/+git/livecd-rootfs:fix-canary-build into livecd-rootfs:ubuntu/master.