message: Set the coinbase tx to be empty in case of proof of stake
diff: @@ -143,7 +143,7 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
  // Add dummy coinbase tx as first transaction
  pblock->vtx.emplace_back();
  - // Add dummy coinstake tx as second transaction
  + // Add dummy coinstake tx as sec transaction
  if(fProofOfStake)
  pblock->vtx.emplace_back();
  pblocktemplate->vTxFees.push_back(-1); // updated at end
  @@ -183,8 +183,17 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
  coinbaseTx.vin.resize(1);
  coinbaseTx.vin[0].prevout.SetNull();
  coinbaseTx.vout.resize(1);
  + coinbaseTx.nTime = GetAdjustedTime();
  + if (fProofOfStake)
  + {
  + // Make the coinbase tx empty in case of proof of stake
  + coinbaseTx.vout[0].SetEmpty();
  + }
  + else
  + {
  coinbaseTx.vout[0].scriptPubKey = scriptPubKeyIn;
  coinbaseTx.vout[0].nValue = nFees + GetBlockSubsidy(nHeight, chainparams.GetConsensus());
  + }
  coinbaseTx.vin[0].scriptSig = CScript() << nHeight << OP_0;
  pblock->vtx[0] = MakeTransactionRef(std::move(coinbaseTx));
  