etc/config.*: tweak the config examples

The main impulse was to have 'hints > iterate', as people usually expect
hints to take precendence before cache.
31 jobs for config-examples in 4 minutes and 7 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Build
passed #208180
amd64 linux docker
build:asan:linux:amd64

00:01:12

passed #208179
amd64 linux docker
build:clang:linux:amd64

00:01:00

passed #208178
amd64 linux docker
build:linux:amd64

00:01:13

passed #208181
amd64 linux docker
srpm

00:00:44

 
  Test
passed #208189
amd64 linux docker
deckard:linux:amd64

00:01:40

passed #208197
privileged
distro:epel-7

00:02:04

passed #208196
privileged
distro:fedora-29

00:02:32

passed #208188
docker
doc

00:00:41

passed #208186
dind
docker:build

00:02:14

passed #208187
amd64 linux docker
installcheck:linux:amd64

00:00:52

passed #208190
amd64 linux docker
installcheck:valgrind:linux:amd64

00:01:44

passed #208183
docker
lint:c

00:02:53

passed #208184
docker
lint:clang-scan-build

00:01:04

passed #208182
docker
lint:lua

00:00:26

canceled #208191
docker
osx:build

passed #208193
amd64 linux docker
pytests:lint

00:00:30

passed #208194
amd64 linux docker
pytests:run

00:01:48

passed #208195
amd64 linux docker
respdiff:iter:udp:linux:amd64

00:02:16

passed #208185
amd64 linux docker
test:linux:amd64

00:00:57

passed #208192
amd64 linux docker
test:linux:amd64:valgrind

00:01:14

 
  Extended
skipped #208198
amd64 linux docker
pytests:extended
skipped #208199
respdiff
respdiff:fwd-tls6-kresd.udp6
skipped #208200
respdiff
respdiff:fwd-udp6-kresd.udp6
skipped #208204
respdiff
respdiff:fwd-udp6-unbound.tcp6
skipped #208205
respdiff
respdiff:fwd-udp6-unbound.tls6
skipped #208203
respdiff
respdiff:fwd-udp6-unbound.udp6
skipped #208202
respdiff
respdiff:iter.tls6
skipped #208201
respdiff
respdiff:iter.udp6
skipped #208206
respdiff
resperf:fwd-tls6.udp-asan
skipped #208207
respdiff
resperf:fwd-udp6.udp-asan
skipped #208208
respdiff
resperf:iter.udp-asan