Title: #397: cleanup: Remove CONFDB_DOMAIN_LEGACY_PASS
Since CONFDB_DOMAIN_LEGACY_PASS is legacy parameter that is rooted in pre-1.0 SSSD. We
should just nuke it as we remove other legacy code.
To pull the PR as Git branch:
git remote add ghsssd https://github.com/SSSD/sssd
git fetch ghsssd pull/397/head:pr397
git checkout pr397