doc: fix generating sphinx doc using older packages

14 jobs for fix-sphinx-rtd-theme in 8 minutes and 3 seconds (queued for 11 seconds)
Status Job ID Name Coverage
  Build
passed #101815
docker linux amd64
build:clang:linux:amd64

00:00:29

passed #101814
docker linux amd64
build:linux:amd64

00:00:27

 
  Test
passed #101821
docker linux amd64
deckard:linux:amd64

00:07:14

passed #101820
docker linux amd64
installcheck:linux:amd64

00:01:29

passed #101822
docker linux amd64
installcheck:valgrind:linux:amd64

00:02:02

passed #101817
docker
lint:c

00:02:38

failed #101818
docker allowed to fail
lint:clang-scan-build

00:01:31

passed #101816
docker
lint:lua

00:01:01

passed #101825
docker linux amd64
respdiff:iter:tcp:linux:amd64

00:02:22

passed #101826
docker linux amd64
respdiff:iter:tls:linux:amd64

00:02:14

passed #101824
docker linux amd64
respdiff:iter:udp:linux:amd64

00:02:22

passed #101819
docker linux amd64
test:linux:amd64

00:01:30

passed #101823
docker linux amd64
test:linux:amd64:valgrind

00:00:56

 
  Coverage
passed #101827
docker linux amd64
coverage

00:00:18

66.7%
 
Name Stage Failure
failed
lint:clang-scan-build Test There is an unknown failure, please try again
  CCLD	modules/hints/hints.so
CCLD modules/cookies/cookies.so
CCLD modules/stats/stats.so
scan-build: 27 bugs found.
scan-build: Run 'scan-view /builds/knot/knot-resolver/scan-results/2018-01-23-182546-13-1' to examine bug reports.
Uploading artifacts...
scan-results: found 32 matching files
Uploading artifacts to coordinator... ok
id=101818 responseStatus=201 Created token=5_W6vVYz
ERROR: Job failed: exit code 1