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.
```
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.");
    }
    if (!IsHex(request.params[0].get_str()))
        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Pubkey must be a hex string");
    std::vector<unsigned char> data(ParseHex(request.params[0].get_str()));
    CPubKey pubKey(data);
    if (!pubKey.IsFullyValid())
        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Pubkey is not a valid public key");
    {
        LOCK(pwallet->cs_wallet);
        std::set<CScript> script_pub_keys;
        for (const auto& dest : GetAllDestinationsForKey(pubKey)) {
            script_pub_keys.insert(GetScriptForDestination(dest));
        }
        pwallet->MarkDirty();