message: Fix missing wallet lock in StoreAndLoadSaplingZkeys.
  Every assertLockHeld was failing.
diff: @@ -33,7 +33,7 @@ BOOST_AUTO_TEST_CASE(StoreAndLoadSaplingZkeys) {
  SelectParams(CBaseChainParams::MAIN);
  CWallet wallet;
  -
  + LOCK(wallet.cs_wallet);
  // wallet should be empty
  std::set<libzcash::SaplingPaymentAddress> addrs;
  wallet.GetSaplingPaymentAddresses(addrs);
  