[freeipa PR#5906][opened] [Backport][ipa-4-9] webui tests: fix algo for finding available idrange

[rcritten]

   URL: https://github.com/freeipa/freeipa/pull/5906
Author: rcritten
 Title: #5906: [Backport][ipa-4-9] webui tests: fix algo for finding available idrange
Action: opened

PR body:
"""
This PR was opened automatically because PR #5902 was pushed to master and backport to
ipa-4-9 is required.
"""

To pull the PR as Git branch:
git remote add ghfreeipa https://github.com/freeipa/freeipa
git fetch ghfreeipa pull/5906/head:pr5906
git checkout pr5906