log improvements in p2p_compactblocks

Summary:
Removing the tabs was missed in D499
The "Running tests" log message is uneccessary. It was added by core because they had two sets of tests (pre-segwit and post-segwit)

Test Plan: ninja check-functional

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien, bytesofman

Differential Revision: https://reviews.bitcoinabc.org/D15110