message: don't duplicate function call
diff: @@ -120,7 +120,7 @@ bool CZPivStake::CreateTxIn(CWallet* pwallet, CTxIn& txIn, uint256 hashTxOut)
  return error("%s: serial extract is less than v2", __func__);
  CZerocoinSpendReceipt receipt;
  - if (!pwallet->MintToTxIn(mint, hashTxOut, txIn, receipt, libzerocoin::SpendType::STAKE, GetIndexFrom()))
  + if (!pwallet->MintToTxIn(mint, hashTxOut, txIn, receipt, libzerocoin::SpendType::STAKE, pindexCheckpoint))
  return error("%s\n", receipt.GetStatusMessage());
  return true;
  