dtv-scan-tables: use a slightly older commit hash

The commit hash chosen by Yann exists in the repository accessible by
git://, but not the one accessible by http://, which is lagging 3
commits behind the git:// repository, for some reason.

For the time being, revert to the latest commit available in the
http:// repository.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>