Code review comment for lp:~bladernr/maas-cert-server/mcs-install-curtin_userdata-by-packaging

I've done a simple test upgrade using this version and it seemed to go OK. Based on that and your comment in the bug report that you've tested it more extensively yourself, I'll approve this. That said, I think that this change interacts with others we've been considering, so we may end up making further changes in the not-too-distant future. I'll comment more in the bug report....