[backport#11590] [Wallet] always show help-line of wallet encryption calls

Summary:
https://github.com/bitcoin/bitcoin/pull/11590/commits/720d9e8fa1d1c7516e8278eaaf60789d2f2c8a53

Backport of Core PR11590

Test Plan:

ninja

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D6593