Title: #5870: [Backport][ipa-4-9] rpcserver.py: perf_counter_ns is Python 3.7+
This PR was opened automatically because PR #5852 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/5870/head:pr5870
git checkout pr5870