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
}
```
nTargetSize = kpSize;
        else
            nTargetSize = std::max(gArgs.GetIntArg("-keypool", DEFAULT_KEYPOOL_SIZE), (int64_t) 0);
        
        
        int64_t missingExternal = std::max(std::max((int64_t) nTargetSize, (int64_t) 1) - (int64_t)setExternalKeyPool.size(), (int64_t) 0);
        int64_t missingInternal = std::max(std::max((int64_t) nTargetSize, (int64_t) 1) - (int64_t)setInternalKeyPool.size(), (int64_t) 0);
        if (!IsHDEnabled() || !m_storage.CanSupportFeature(FEATURE_HD_SPLIT))
        {
            
            missingInternal = 0;
        }
        bool internal = false;
        WalletBatch batch(m_storage.GetDatabase());
        for (int64_t i = missingInternal + missingExternal; i--;)
        {
            if (i < missingInternal) {
                internal = true;
            }
            CPubKey pubkey(GenerateNewKey(batch, m_hd_chain, internal));
            AddKeypoolPubkeyWithDB(pubkey, internal, batch);
        }
        if (missingInternal + missingExternal > 0) {
            WalletLogPrintf("keypool added %d keys (%d internal), size=%u (%u internal)\n", missingInternal + missingExternal, missingInternal, setInternalKeyPool.size() + setExternalKeyPool.size() + set_pre_split_keypool.size(), setInternalKeyPool.size());
        }
    }
    NotifyCanGetAddressesChanged();
    return true;
}
void LegacyScriptPubKeyMan::AddKeypoolPubkeyWithDB(const CPubKey& pubkey, const bool internal, WalletBatch& batch)