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
```
},
                RPCExamples{
                    HelpExampleCli("loadwallet", "\"test.dat\"")
            + HelpExampleRpc("loadwallet", "\"test.dat\"")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
    WalletContext& context = EnsureWalletContext(request.context);
    const std::string name(request.params[0].get_str());
    DatabaseOptions options;
    DatabaseStatus status;
    options.require_existing = true;
    bilingual_str error;
    std::vector<bilingual_str> warnings;
    Optional<bool> load_on_start = request.params[1].isNull() ? nullopt : Optional<bool>(request.params[1].get_bool());
    std::shared_ptr<CWallet> const wallet = LoadWallet(*context.chain, name, load_on_start, options, status, error, warnings);
    if (!wallet) {
        
        
        RPCErrorCode code = status == DatabaseStatus::FAILED_NOT_FOUND || status == DatabaseStatus::FAILED_BAD_FORMAT ? RPC_WALLET_NOT_FOUND : RPC_WALLET_ERROR;
        throw JSONRPCError(code, error.original);
    }
    UniValue obj(UniValue::VOBJ);
    obj.pushKV("name", wallet->GetName());
    obj.pushKV("warning", Join(warnings, Untranslated("\n")).original);
    return obj;
},
    };
}
static RPCHelpMan setwalletflag()