Also remove misleading comment. ClearBanned is used by rpc as well.
This is a partial backport of Core PR14605 : https://github.com/bitcoin/bitcoin/pull/14605/commits/84fc3fbd0304a7d6e660bf783c84bed2dd415141daae598feb034f2f56e0b00ecfb4854d693d3641
Depends on D4126