message: Add key's size checking before lookup
diff: @@ -239,7 +239,8 @@ void CMPMintList::DeleteAll(int32_t startBlock)
  auto firstKey = CreateSequenceKey(0);
  - while (it->Valid() && it->key().data()[0] == static_cast<char>(KeyType::Sequence)) {
  + while (it->Valid() &&
  + (it->key().size() > 0 && it->key().data()[0] == static_cast<char>(KeyType::Sequence))) {
  int32_t mintBlock;
  std::string rawMint;
  