message: [Bug][Wallet] Guard chainActive access in GetMintMaturityHeight
diff: @@ -892,7 +892,8 @@ std::map<libzerocoin::CoinDenomination, int> GetMintMaturityHeight()
  std::map<libzerocoin::CoinDenomination, std::pair<int, int > > mapDenomMaturity;
  for (auto denom : libzerocoin::zerocoinDenomList)
  mapDenomMaturity.insert(std::make_pair(denom, std::make_pair(0, 0)));
  -
  + {
  + LOCK(cs_main);
  int nConfirmedHeight = chainActive.Height() - Params().Zerocoin_MintRequiredConfirmations();
  // A mint need to get to at least the min maturity height before it will spend.
  @@ -920,6 +921,7 @@ std::map<libzerocoin::CoinDenomination, int> GetMintMaturityHeight()
  break;
  pindex = chainActive[pindex->nHeight - 1];
  }
  + }
  //Generate final map
  std::map<libzerocoin::CoinDenomination, int> mapRet;
  