Fix another kasp test timing issue
In the cases where we test SOA serial updates and TTL updates, we check if for "all zones loaded" to ensure the new zone content is loaded. But this is the unsigned zone, the signed zone still needs to be produced.
There is thus a timing issue where the dig request comes in before the signing process has finished.
Add a retry quiet to mitigate against it.
Closes #3362 (closed)