Have this warning while building current master (0bd4929cd00e91bf4137f43b097cd62f72f503e4) on one test machine.
```
wallet/rpcwallet.cpp: In function 'rescanblockchain()::<lambda(const RPCHelpMan&, const JSONRPCRequest&)>':
wallet/rpcwallet.cpp:3596:19: warning: '*((void*)& stop_height +4)' may be used uninitialized in this function [-Wmaybe-uninitialized]
 3596 |     Optional<int> stop_height;
      |                   ^~~~~~~~~~~
```
```
$ gcc --version
gcc (Gentoo 9.2.0-r2 p3) 9.2.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ uname -a
Linux red-box 4.19.72-gentoo #2 SMP Sun Sep 22 03:00:01 EEST 2019 x86_64 Intel(R) Pentium(R) CPU N3710 @ 1.60GHz GenuineIntel GNU/Linux
```
fIncludeEmpty = params[1].get_bool();
    isminefilter filter = ISMINE_SPENDABLE;
    if (ParseIncludeWatchonly(params[2], *pwallet)) {
        filter |= ISMINE_WATCH_ONLY;
    }
    bool has_filtered_address = false;
    CTxDestination filtered_address = CNoDestination();
    if (!by_label && params.size() > 3) {
        if (!IsValidDestinationString(params[3].get_str())) {
            throw JSONRPCError(RPC_WALLET_ERROR, "address_filter parameter was invalid");
        }
        filtered_address = DecodeDestination(params[3].get_str());
        has_filtered_address = true;
    }
    
    std::map<CTxDestination, tallyitem> mapTally;
    for (const std::pair<const uint256, CWalletTx>& pairWtx : pwallet->mapWallet) {
        const CWalletTx& wtx = pairWtx.second;
        if (wtx.IsCoinBase() || !pwallet->chain().checkFinalTx(*wtx.tx)) {
            continue;
        }
        int nDepth = wtx.GetDepthInMainChain();
        if (nDepth < nMinDepth)
            continue;
        for (const CTxOut& txout : wtx.tx->vout)
        {
            CTxDestination address;
            if (!ExtractDestination(txout.scriptPubKey, address))
                continue;
            if (has_filtered_address && !(filtered_address == address)) {