BUG/MINOR: acme: handle multiple auth with the same name

BUG/MINOR: acme: handle multiple auth with the same name

In case of the dns-01 challenge, it is possible to have a domain
"example.com" and "*.example.com" in the same request. This will create
2 different auth objects, which need 2 different challenges.

However the associated domain is "example.com" for both auth objects.

When doing a "challenge_ready", the algorithm will break at the first
domain found. But since you can have multiple time the same domain in
this case, breaking at the first one prevent to have all auth objects in
a ready state.

This patch just remove the break so we can loop on every auth objects.

Must be backported to 3.2.