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
```
{
    return RPCHelpMan{
                "listunspent",
                "\nReturns array of unspent transaction outputs\n"
                "with between minconf and maxconf (inclusive) confirmations.\n"
                "Optionally filter to only include txouts paid to specified addresses.\n",
                {
                    {"minconf", RPCArg::Type::NUM,  "1", "The minimum confirmations to filter"},
                    {"maxconf", RPCArg::Type::NUM,  "9999999", "The maximum confirmations to filter"},
                    {"addresses", RPCArg::Type::ARR,  "empty array", "The bitcoin addresses to filter",
                        {
                            {"address", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "bitcoin address"},
                        },
                    },
                    {"include_unsafe", RPCArg::Type::BOOL,  "true", "Include outputs that are not safe to spend\n"
                              "See description of \"safe\" attribute below."},
                    {"query_options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "JSON with query options",
                        {
                            {"minimumAmount", RPCArg::Type::AMOUNT,  "0", "Minimum value of each UTXO in " + CURRENCY_UNIT + ""},