Revert removal of code block

Summary: Reverts the removal of a code block in D301 that is making backporting difficult and adds little value otherwise.

Test Plan:
make check
test_runner.py

Reviewers: deadalnix, Fabien, #bitcoin_abc

Reviewed By: Fabien, #bitcoin_abc

Subscribers: markblundeberg

Differential Revision: https://reviews.bitcoinabc.org/D2976