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
```
{
    if (IsValidDestination(dest)) {
        entry.pushKV("address", EncodeDestination(dest));
    }
}
/**
 * List transactions based on the given criteria.
 *
 * @param  pwallet        The wallet.
 * @param  wtx            The wallet transaction.
 * @param  nMinDepth      The minimum confirmation depth.
 * @param  fLong          Whether to include the JSON version of the transaction.
 * @param  ret            The UniValue into which the result is stored.
 * @param  filter_ismine  The "is mine" filter flags.
 * @param  filter_label   Optional label string to filter incoming transactions.
 */
static void ListTransactions(const CWallet* const pwallet, const CWalletTx& wtx, int nMinDepth, bool fLong, UniValue& ret, const isminefilter& filter_ismine, const std::string* filter_label) EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)
{
    CAmount nFee;
    std::list<COutputEntry> listReceived;
    std::list<COutputEntry> listSent;
    wtx.GetAmounts(listReceived, listSent, nFee, filter_ismine);
    bool involvesWatchonly = wtx.IsFromMe(ISMINE_WATCH_ONLY);
    
    if (!filter_label)
    {
        for (const COutputEntry& s : listSent)
        {
            UniValue entry(UniValue::VOBJ);