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
```
"       \"NONE\"\n"
            "       \"SINGLE\"\n"
            "       \"ALL|ANYONECANPAY\"\n"
            "       \"NONE|ANYONECANPAY\"\n"
            "       \"SINGLE|ANYONECANPAY\""},
                },
                RPCResult{
                    RPCResult::Type::OBJ, "", "",
                    {
                        {RPCResult::Type::STR_HEX, "hex", "The hex-encoded raw transaction with signature(s)"},
                        {RPCResult::Type::BOOL, "complete", "If the transaction has a complete set of signatures"},
                        {RPCResult::Type::ARR, "errors",  true, "Script verification errors (if there are any)",
                        {
                            {RPCResult::Type::OBJ, "", "",
                            {
                                {RPCResult::Type::STR_HEX, "txid", "The hash of the referenced, previous transaction"},
                                {RPCResult::Type::NUM, "vout", "The index of the output to spent and used as input"},
                                {RPCResult::Type::STR_HEX, "scriptSig", "The hex-encoded signature script"},
                                {RPCResult::Type::NUM, "sequence", "Script sequence number"},
                                {RPCResult::Type::STR, "error", "Verification or signing error related to the input"},
                            }},
                        }},
                    }
                },
                RPCExamples{
                    HelpExampleCli("signrawtransactionwithwallet", "\"myhex\"")
            + HelpExampleRpc("signrawtransactionwithwallet", "\"myhex\"")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{