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.


{
    
    CAutoFile fileout(OpenUndoFile(pos), SER_DISK, CLIENT_VERSION);
    if (fileout.IsNull())
        return error("%s: OpenUndoFile failed", __func__);
    
    unsigned int nSize = GetSerializeSize(blockundo, fileout.GetVersion());
    fileout << messageStart << nSize;
    
    long fileOutPos = ftell(fileout.Get());
    if (fileOutPos < 0)
        return error("%s: ftell failed", __func__);
    pos.nPos = (unsigned int)fileOutPos;
    fileout << blockundo;
    
    CHashWriter hasher(SER_GETHASH, PROTOCOL_VERSION);
    hasher << hashBlock;
    hasher << blockundo;
    fileout << hasher.GetHash();
    return true;
}
bool UndoReadFromDisk(CBlockUndo& blockundo, const CBlockIndex* pindex)