message: Fix getbalance to return only non-mints output
diff: @@ -1745,7 +1745,8 @@ CAmount CWalletTx::GetAvailableCredit(bool fUseCache) const {
  for (unsigned int i = 0; i < vout.size(); i++) {
  if (!pwallet->IsSpent(hashTx, i)) {
  const CTxOut &txout = vout[i];
  - nCredit += pwallet->GetCredit(txout, ISMINE_SPENDABLE);
  + bool isPrivate = txout.scriptPubKey.IsZerocoinMint() || txout.scriptPubKey.IsZerocoinMintV3();
  + nCredit += isPrivate ? 0 : pwallet->GetCredit(txout, ISMINE_SPENDABLE);
  if (!MoneyRange(nCredit))
  throw std::runtime_error("CWalletTx::GetAvailableCredit() : value out of range");
  }
  