[9.18] Do not retry in resolution_fails() on timeout

At the time of test number (19), there were 10 "sending packet to 10.53.0.7" lines in the "legacy/ns1/named.run" file; usually, only seven are present:

I:legacy:checking recursive lookup to edns 512 + no tcp server does not cause query loops (19)
I:legacy:ns1 sent 10 queries to ns7, expected less than 10
I:legacy:failed

Those three can be attributed to tests "8", "10", and "18", where the dig of "resolution_fails()" retried after a timeout to succeed with "status: SERVFAIL" subsequently, as seen in each of dig.out.test{8,10,18} files.

;; communications error to 10.53.0.1#13093: timed out

; <<>> DiG 9.19.12-dev <<>> -p 13093 +tcp @10.53.0.1 edns512-notcp. TXT
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 5368
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

This retry is unnecessary because "resolution_fails()" considers timeout a positive result.

(cherry picked from commit e05460c8)

Closes #3916 (closed)

Backport of MR !7814 (merged)