I have 2 legacy wallets and on both if I run `upgradewallet` it will cause bitcoin core to crash. This should just return me an error string

Currenl result from `getwalletinfo`:
```
{
  "walletname": "Wallet",
  "walletversion": 169900,
  "format": "bdb",
  "balance": 0.00000000,
  "unconfirmed_balance": 0.00000000,
  "immature_balance": 0.00000000,
  "txcount": 80,
  "keypoololdest": 1613078825,
  "keypoolsize": 941,
  "keypoolsize_hd_internal": 941,
  "paytxfee": 0.00000000,
  "private_keys_enabled": false,
  "avoid_reuse": true,
  "scanning": false,
  "descriptors": false
}
```
{
    LOCK(cs_desc_man);
    std::vector<WalletDestination> result;
    if (IsMine(script)) {
        int32_t index = m_map_script_pub_keys[script];
        if (index >= m_wallet_descriptor.next_index) {
            WalletLogPrintf("%s: Detected a used keypool item at index %d, mark all keypool items up to this item as used\n", __func__, index);
            auto out_keys = std::make_unique<FlatSigningProvider>();
            std::vector<CScript> scripts_temp;
            while (index >= m_wallet_descriptor.next_index) {
                if (!m_wallet_descriptor.descriptor->ExpandFromCache(m_wallet_descriptor.next_index, m_wallet_descriptor.cache, scripts_temp, *out_keys)) {
                    throw std::runtime_error(std::string(__func__) + ": Unable to expand descriptor from cache");
                }
                CTxDestination dest;
                ExtractDestination(scripts_temp[0], dest);
                result.push_back({dest, std::nullopt});
                m_wallet_descriptor.next_index++;
            }
        }
        if (!TopUp()) {
            WalletLogPrintf("%s: Topping up keypool failed (locked wallet)\n", __func__);
        }
    }
    return result;
}
void DescriptorScriptPubKeyMan::AddDescriptorKey(const CKey& key, const CPubKey &pubkey)