[dnsdist] dnsdist timeout with unknown opcode query

[Stephane Bortzmeyer]

On Wed, Sep 23, 2020 at 04:56:05PM +0200,
 Remi Gacogne via dnsdist <dnsdist at mailman.powerdns.com> wrote 
 a message of 76 lines which said:

> +header-only instructs dig to send a query without a question
> section (qdcount is 0), and dnsdist doesn't support that. The query
> is deemed invalid and discarded before any counter can be
> incremented.

But in that case, surely dnsdist should reply FORMERR instead?