Title: #1167: [Backport][ipa-4-6] p11-kit: add serial number in DER format
This PR was opened automatically because PR #1156 was pushed to master and backport to
ipa-4-6 is required.
To pull the PR as Git branch:
git remote add ghfreeipa https://github.com/freeipa/freeipa
git fetch ghfreeipa pull/1167/head:pr1167
git checkout pr1167