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.
```
RPCResult{RPCResult::Type::NONE, "", ""},
                RPCExamples{
            "\nImport an address with rescan\n"
            + HelpExampleCli("importaddress", "\"myaddress\"") +
            "\nImport using a label without rescan\n"
            + HelpExampleCli("importaddress", "\"myaddress\" \"testing\" false") +
            "\nAs a JSON-RPC call\n"
            + HelpExampleRpc("importaddress", "\"myaddress\", \"testing\", false")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
    std::shared_ptr<CWallet> const pwallet = GetWalletForJSONRPCRequest(request);
    if (!pwallet) return UniValue::VNULL;
    EnsureLegacyScriptPubKeyMan(*pwallet, true);
    std::string strLabel;
    if (!request.params[1].isNull())
        strLabel = request.params[1].get_str();
    
    bool fRescan = true;
    if (!request.params[2].isNull())
        fRescan = request.params[2].get_bool();
    if (fRescan && pwallet->chain().havePruned()) {
        
        
        
        throw JSONRPCError(RPC_WALLET_ERROR, "Rescan is disabled when blocks are pruned");
    }
    WalletRescanReserver reserver(*pwallet);
    if (fRescan && !reserver.reserve()) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Wallet is currently rescanning. Abort existing rescan or wait.");