Revert "When re-using runners when reloading, reload their configuration"
This reverts commit 770f8d64.
The commit didn't actually fix the bug. The issue was that the RunnerManager had no way of knowing if the KCMs get changes, because in KF5 we moved the entire runner config stuff out-of-process.
And the original issue got solved by the KConfigWatcher, see !7 (diffs).
If we leave the code in we have an unnecessary config reloading when we enable/disable runners in the KCMs. @davidedmundson You mentioned this when reviewing.