tweak auto-unparking message
Summary:
- UnparkBlock will only get called once per chain, i.e., we only see one
log message regardless of how many blocks got unparked on that chain,
since UnparkBlock will unpark all ancestors of pindexTest and it
results in everything from genesis to pindexNew being unparked. So
"unpark chain" rather than "unpark block" makes more sense as a message,
as I'd expect to see the latter one for every single block.
- Ideally when this message happens we should be in a state where
pindexNew == pindexTest, however it might somehow happen that this
isn't the case and we should print the tip of the chain that is being
unparked.
Test Plan: ninja check
Reviewers: #bitcoin_abc, deadalnix
Reviewed By: #bitcoin_abc, deadalnix
Subscribers: Fabien
Differential Revision: https://reviews.bitcoinabc.org/D4937