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
```
continue;
            }
            isminefilter mine = pwallet->IsMine(address);
            if(!(mine & filter))
                continue;
            tallyitem& item = mapTally[address];
            item.nAmount += txout.nValue;
            item.nConf = std::min(item.nConf, nDepth);
            item.txids.push_back(wtx.GetHash());
            if (mine & ISMINE_WATCH_ONLY)
                item.fIsWatchonly = true;
        }
    }
    
    UniValue ret(UniValue::VARR);
    std::map<std::string, tallyitem> label_tally;
    
    
    auto start = pwallet->m_address_book.begin();
    auto end = pwallet->m_address_book.end();
    
    if (has_filtered_address) {
        start = pwallet->m_address_book.find(filtered_address);
        if (start != end) {
            end = std::next(start);
        }
    }
    for (auto item_it = start; item_it != end; ++item_it)
    {
        if (item_it->second.IsChange()) continue;