Fix problem with DNS retries in 2.83/2.84.
The new logic in 2.83/2.84 which merges distinct requests
for the same domain causes problems with clients which do
retries as distinct requests (differing IDs and/or source ports.)
The retries just get piggy-backed on the first, failed, request.
The logic is now changed so that distinct requests for repeated
queries still get merged into a single ID/source port, but
they now always trigger a re-try upstream.
Thanks to Nicholas Mu for his analysis.
Tweak sort order of tags in get-