message: Fix chainstate serialized_size computation
  backports bitcoin@298e040bca0aad62b616a1d3e66e1e44d2b9bd3a
diff: @@ -133,7 +133,7 @@ bool CCoinsViewDB::GetStats(CCoinsStats& stats) const
  nTotalAmount += out.nValue;
  }
  }
  - stats.nSerializedSize += 32 + pcursor->GetKeySize();
  + stats.nSerializedSize += 32 + pcursor->GetValueSize();
  ss << VARINT(0);
  } else {
  return error("CCoinsViewDB::GetStats() : unable to read value");
  