Previously the seed was stored with keypath 'm' so we need to skip this as well when determining inactive seeds.
Partial backport of core PR19054:
https://github.com/bitcoin/bitcoin/pull/19054/commits/3a03a11e8c696e2164b8bb221a4a35a7c3ac4d6d
This unbreaks opening the wallets (since D9196) that were created before
D4175.
There is a second commit with an upgrade test which requires some work
to be ported.