Revert "test: Show debug log on unit test failure"
This reverts rABCee4e128c034d2ce2a50bf4df4e90b49b5709dfbe.
This cause segmentation faults. The fixture triggers a double free.
Test Plan: @Fabien was able to consistently reproduce the issue with ASAN and bisected it to this commit.
Reviewers: #bitcoin_abc, Fabien
Reviewed By: #bitcoin_abc, Fabien
Differential Revision: https://reviews.bitcoinabc.org/D9990