message: Remove wallet lock on staking thread to prevent deadlock.
diff: @@ -2406,7 +2406,7 @@ CAmount CWallet::GetMintableBalance(std::vector<COutput>& vMintableCoins) const
  vMintableCoins.clear();
  CAmount balance = 0;
  std::vector<COutput> vCoins;
  - AvailableCoins(vCoins, true);
  + AvailableCoins(vCoins, true, nullptr, 1, MAX_MONEY, 0, Params().CoinbaseMaturity()+1);
  for (const COutput& coin : vCoins) {
  CTxDestination address;
  if (coin.fSpendable) {
  @@ -3420,7 +3420,6 @@ bool CWallet::CreateCoinStake(unsigned int nBits, CMutableTransaction& txNew, un
  uint256 hashTxOut = txNew.GetOutputsHash();
  CTxIn in;
  {
  - LOCK(cs_wallet);
  if (!stakeInput->CreateTxIn(this, in, hashTxOut)) {
  LogPrintf("%s : failed to create TxIn\n", __func__);
  txNew.vin.clear();
  