[dnsdist] dnsdist latency bucket metric still broken in 1.8.0?

[Christoph]

Remi Gacogne via dnsdist:
> The fix not being backported is an oversight, I added the "backport to 
> 1.7.x" flag so we include it in an upcoming 1.7.x release.

Great to hear that this was unexptected.

>> Recently we upgraded our dnsdist instances to 1.8.0
>> but the upgrade did not improve the values in dnsdist_latency_bucket.
>> Now after the upgrade, the graph show basically a flat line.
>> This only affects our FreeBSD servers, not our Debian based dnsdist 
>> instances.
> 
> That's weird. Would you be able to share the prometheus output, or the 
> dumpStats() one, so we know if this is the same bug or a related one?

I added it here because I wanted to add the graph as well but github 
upload is failing me, so just prometheus:
https://github.com/PowerDNS/pdns/issues/11239#issuecomment-1507536007

thanks for looking into it!
Christoph