[backport#17261 8/13] HD Split: Avoid redundant upgrades

Summary:
This avoids repeaded upgrades when support for more multiple keyman references
is added in the next commit:
https://github.com/bitcoin/bitcoin/pull/16341#discussion_r322370108

https://github.com/bitcoin/bitcoin/pull/17261/commits/415afcccd3e5583defdb76e3a280f48e98983301

Depends on D7854

Partial backport of Core PR17261

Test Plan:

ninja all check check-functional

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D7855