[dns-operations] Problems resolving .gov using DLV

[Florian Weimer]

* Michael Sinatra:

> Doing a crash upgrade to 9.6.0-P1 appears to fix the problem.
>
> Is it possible that gov started using an algorithm that BIND 9.5.1-P1
> doesn't support?

It's signed using NSEC3 (which provides some obfuscation of zone
contents), and BIND 9.6 implements that.