I get a lot of spurious messages like this in the log:
```
2019-08-31T18:07:53Z Synchronizing blockheaders, height: 592633 (~100.00%)
2019-08-31T18:09:40Z Synchronizing blockheaders, height: 592634 (~100.00%)
2019-08-31T18:09:40Z Synchronizing blockheaders, height: 592634 (~100.00%)
2019-08-31T18:09:40Z Synchronizing blockheaders, height: 592634 (~100.00%)
2019-08-31T18:09:40Z Synchronizing blockheaders, height: 592634 (~100.00%)
2019-08-31T18:09:40Z Synchronizing blockheaders, height: 592634 (~100.00%)
2019-08-31T18:10:28Z Synchronizing blockheaders, height: 592635 (~100.00%)
2019-08-31T18:10:28Z Synchronizing blockheaders, height: 592635 (~100.00%)
2019-08-31T18:10:28Z Synchronizing blockheaders, height: 592635 (~100.00%)
2019-08-31T18:10:28Z Synchronizing blockheaders, height: 592635 (~100.00%)
2019-08-31T18:10:28Z Synchronizing blockheaders, height: 592635 (~100.00%)
2019-08-31T18:11:01Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:11:01Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:11:01Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:11:01Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:11:01Z Synchronizing blockheaders, height: 592636 (~100.00%)
```
also
```
2019-08-31T18:19:47Z New outbound peer connected: version: 70015, blocks=592636, peer=0
2019-08-31T18:19:47Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:19:47Z New outbound peer connected: version: 70015, blocks=592636, peer=1
2019-08-31T18:19:48Z Synchronizing blockheaders, height: 592636 (~100.00%)
2019-08-31T18:19:48Z New outbound peer connected: version: 70015, blocks=592636, peer=2
2019-08-31T18:19:49Z Synchronizing blockheaders, height: 592636 (~100.00%)
```
This log message was introduced in #15615 by @jonasschnelli..
From what I understand, it's supposed to only be shown once per 2000 blocks, not multiple times for the same block.


AssertLockNotHeld(cs_main);
    if (GetMainSignals().CallbacksPending() > 10) {
        SyncWithValidationInterfaceQueue();
    }
}
/**
 * Make the best chain active, in multiple steps. The result is either failure
 * or an activated best chain. pblock is either nullptr or a pointer to a block
 * that is already loaded (to avoid loading it again from disk).
 *
 * ActivateBestChain is split into steps (see ActivateBestChainStep) so that
 * we avoid holding cs_main for an extended period of time; the length of this
 * call may be quite long during reindexing or a substantial reorg.
 */
bool CChainState::ActivateBestChain(CValidationState &state, const CChainParams& chainparams, std::shared_ptr<const CBlock> pblock) {