message: Remove unnecessary const_cast
diff: @@ -4347,7 +4347,7 @@ bool CChainState::LoadGenesisBlock(const CChainParams& chainparams)
  return true;
  try {
  - CBlock &block = const_cast<CBlock&>(chainparams.GenesisBlock());
  + const CBlock& block = chainparams.GenesisBlock();
  CDiskBlockPos blockPos = SaveBlockToDisk(block, 0, chainparams, nullptr);
  if (blockPos.IsNull())
  return error("%s: writing genesis block to disk failed", __func__);
  