A lookup whose RIR query failed, or whose RIR answer carried none of the
WHOIS fields (a refusal of service, for one), returned IANA's answer as
a success. The fetcher stored it as complete with blank fields, did not
look the AS up again for 30 days, and shortened its interval. Such a
lookup is now an error: the fetcher backs off and leaves the row as it
was. The fields are read from the RIR's answer alone. An AS IANA refers
to no RIR is stored with no WHOIS data, so it is not looked up again
until it is stale, counting as neither a success nor a failure. Tests
reach fake WHOIS servers through the client's DialContext.
Model: opus-5-5