cache nitpick: avoid verbose-logging of unitialized TTL

Replaced by a visually recognizable dummy value, for simplicity.
These were introduced in commits:
  cache: don't require cached NS for aggresive answers
  cache closest_NS(): factor out the inside of a loop
24 jobs for ci-respdiff-master in 4 minutes and 49 seconds (queued for 8 seconds)
Status Job ID Name Coverage
  Build
passed #159421
amd64 linux docker
build:clang:linux:amd64

00:00:45

passed #159420
amd64 linux docker
build:linux:amd64

00:00:47

passed #159422
amd64 linux docker allowed to fail
srpm

00:00:25

 
  Test
passed #159429
amd64 linux docker
deckard:linux:amd64

00:01:24

passed #159436
privileged
distro:epel-7

00:02:18

passed #159435
privileged
distro:fedora-27

00:03:02

passed #159428
docker
doc

00:00:46

passed #159427
amd64 linux docker
installcheck:linux:amd64

00:01:07

passed #159430
amd64 linux docker
installcheck:valgrind:linux:amd64

00:01:37

passed #159424
docker
lint:c

00:02:35

failed #159425
docker allowed to fail
lint:clang-scan-build

00:01:18

passed #159423
docker
lint:lua

00:00:36

passed #159433
amd64 linux docker
respdiff:iter:tcp:linux:amd64

00:03:41

passed #159434
amd64 linux docker
respdiff:iter:tls:linux:amd64

00:03:57

passed #159432
amd64 linux docker
respdiff:iter:udp:linux:amd64

00:03:55

passed #159426
amd64 linux docker
test:linux:amd64

00:01:02

passed #159431
amd64 linux docker
test:linux:amd64:valgrind

00:01:16

 
  Respdiff
canceled #159437
respdiff
respdiff:fwd-tls6-kresd.udp6

canceled #159438
respdiff
respdiff:fwd-udp6-kresd.udp6

canceled #159442
respdiff
respdiff:fwd-udp6-unbound.tcp6

canceled #159443
respdiff
respdiff:fwd-udp6-unbound.tls6

canceled #159441
respdiff
respdiff:fwd-udp6-unbound.udp6

canceled #159440
respdiff allowed to fail
respdiff:iter.tls6

canceled #159439
respdiff
respdiff:iter.udp6

 
Name Stage Failure
failed
lint:clang-scan-build Test
                                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
5 warnings generated.
CCLD daemon/kresd
scan-build: 29 bugs found.
scan-build: Run 'scan-view /builds/knot/knot-resolver/scan-results/2018-08-07-131012-14-1' to examine bug reports.
Uploading artifacts...
scan-results: found 34 matching files
Uploading artifacts to coordinator... ok
id=159425 responseStatus=201 Created token=z2aQKWVM
ERROR: Job failed: exit code 1