Comment 2 for bug 1433622

I proposed a fix for this as follows:

https://code.launchpad.net/~mpontillo/maas/bug-1433622-disallow-absolute-fqdn-cluster-names/+merge/254826

The first part of the fix was to disallow "." at the end of the name (and other invalid domain names). Then I took the next step and changed the code to change a domain like "maas." to "maas" under the hood.