message: [Cleanup][Wallet] Don't count zPIV in MintableCoins()
  zPIV are not stakeable anymore. They shouldn't be counted here.
diff: @@ -2180,9 +2180,6 @@ bool CWallet::MintableCoins()
  {
  LOCK(cs_main);
  CAmount nBalance = GetStakingBalance(GetBoolArg("-coldstaking", true));
  - CAmount nZpivBalance = GetZerocoinBalance(false);
  -
  - int chainHeight = chainActive.Height();
  // Regular PIV
  if (nBalance > 0) {
  @@ -2196,25 +2193,16 @@ bool CWallet::MintableCoins()
  const bool fIncludeCold = sporkManager.IsSporkActive(SPORK_17_COLDSTAKING_ENFORCEMENT) && GetBoolArg("-coldstaking", true);
  AvailableCoins(vCoins, true, NULL, false, STAKABLE_COINS, false, 1, fIncludeCold, false);
  - int64_t time = GetAdjustedTime();
  + if (vCoins.size() > 0) {
  + // check that we have at least one utxo eligible for staking (min age/depth)
  + const int64_t time = GetAdjustedTime();
  + const int chainHeight = chainActive.Height();
  for (const COutput& out : vCoins) {
  CBlockIndex* utxoBlock = mapBlockIndex.at(out.tx->hashBlock);
  - //check for maturity (min age/depth)
  if (Params().HasStakeMinAgeOrDepth(chainHeight, time, utxoBlock->nHeight, utxoBlock->nTime))
  return true;
  }
  }
  -
  - // zPIV
  - if (nZpivBalance > 0) {
  - std::set<CMintMeta> setMints = zpivTracker->ListMints(true, true, true);
  - for (auto mint : setMints) {
  - if (mint.nVersion < CZerocoinMint::STAKABLE_VERSION)
  - continue;
  - if (mint.nHeight > chainHeight - Params().Zerocoin_RequiredStakeDepth())
  - continue;
  - return true;
  - }
  }
  return false;
  