WIP: Fix incorrect test vectors.

[nochiel]

Fixes for https://github.com/BlockchainCommons/Research/issues/83.

Ref. https://github.com/BlockchainCommons/sweeptool-cli/issues/1

• papers\bcr-2020-010-output-desc.md
  • [x] Test vector 4.
  • ~[x] Test vector 5.~
    • No changes needed.

[nochiel]

RE; https://github.com/BlockchainCommons/sweeptool-cli/issues/1#issuecomment-879802335 @gorazdko @wolfmcnally Added for discussion as I work on this. Do these changes make sense?