This differs from behaviour of `importaddress` where it works.
```
$ bitcoin-cli importaddress "<address>" "<label>" false
```
vs
```
$ bitcoin-cli importmulti '[{ "scriptPubKey": { "address": "<address>" }, "timestamp":0, "label": "<label>", "watchonly": true }]' '{ "rescan": false }'
error code: -13
error message:
Error: Please enter the wallet passphrase with walletpassphrase first.
```
UniValue warnings(UniValue::VARR);
    UniValue result(UniValue::VOBJ);
    try {
        if (!data.exists("desc")) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Descriptor not found.");
        }
        const std::string& descriptor = data["desc"].get_str();
        const bool active = data.exists("active") ? data["active"].get_bool() : false;
        const bool internal = data.exists("internal") ? data["internal"].get_bool() : false;
        const std::string& label = data.exists("label") ? data["label"].get_str() : "";
        // 
        FlatSigningProvider keys;
        std::string error;
        auto parsed_desc = Parse(descriptor, keys, error, /* rue);
        if (!parsed_desc) {
            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, error);
        }
        // 
        int64_t range_start = 0, range_end = 1, next_index = 0;
        if (!parsed_desc->IsRange() && data.exists("range")) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Range should not be specified for an un-ranged descriptor");
        } else if (parsed_desc->IsRange()) {
            if (data.exists("range")) {
                auto range = ParseDescriptorRange(data["range"]);
                range_start = range.first;
                range_end = range.second + 1; // 
            } else {
                warnings.push_back("Range not given, using default keypool range");
                range_start = 0;
                range_end = gArgs.GetIntArg("-keypool", DEFAULT_KEYPOOL_SIZE);