Title: #5428: [Backport][ipa-4-6] ipatest: fix
This is manual backport of PR #5424 to ipa-4-6 branch. The only difference is that the
test launches a python command instead of python3 (RHEL7 only provides python2-ipalib,
fedora 27 provides both python2-ipalib and python3-ipalib).
To pull the PR as Git branch:
git remote add ghfreeipa https://github.com/freeipa/freeipa
git fetch ghfreeipa pull/5428/head:pr5428
git checkout pr5428