[sphinx] Fixed some sphinx warnings

4 jobs for merge-bob.bio in 15 minutes and 51 seconds (queued for 7 seconds)
Status Name Job ID Coverage
  Build
passed build_linux_36 #212509
docker

00:10:08

59.0%
passed build_linux_37 #212510
docker

00:09:57

59.0%
passed build_macosx_36 #212507
macosx

00:08:18

59.0%
passed build_macosx_37 #212508
macosx

00:15:49

59.0%