system-variables: improve noop functions warning (#6374)#6420

ti-chi-bot merged 2 commits into

pingcap:release-5.1pingcap/docs:release-5.1from

ti-chi-bot:cherry-pick-6374-to-release-5.1ti-chi-bot/docs:cherry-pick-6374-to-release-5.1Copy head branch name to clipboard