[freeipa PR#3801][opened] [Backport][ipa-4-6] ipa-backup: fix python2 issue with os.mkdir

[flo-renaud]

   URL: https://github.com/freeipa/freeipa/pull/3801
Author: flo-renaud
 Title: #3801: [Backport][ipa-4-6] ipa-backup: fix python2 issue with os.mkdir
Action: opened

PR body:
"""
This PR was opened automatically because PR #3794 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/3801/head:pr3801
git checkout pr3801