Comment 2 for bug 1805854

I got some feedback from Phillip.

As of today, the commit message in the MP is correct.

We've decided to limit the auto-selection of those
mirrors to arm, where we know a use case. That way new instances
of ppc64el or other arches will not select them. Such a behavior change
could be problematic for a user in a firewalled environment.

The 'default' path will still end up hitting ports.archive.ubuntu.com.