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
}
```
{
    
    LearnRelatedScripts(key, OutputType::P2SH_SEGWIT);
}
std::vector<CKeyPool> LegacyScriptPubKeyMan::MarkReserveKeysAsUsed(int64_t keypool_id)
{
    AssertLockHeld(cs_KeyStore);
    bool internal = setInternalKeyPool.count(keypool_id);
    if (!internal) assert(setExternalKeyPool.count(keypool_id) || set_pre_split_keypool.count(keypool_id));
    std::set<int64_t> *setKeyPool = internal ? &setInternalKeyPool : (set_pre_split_keypool.empty() ? &setExternalKeyPool : &set_pre_split_keypool);
    auto it = setKeyPool->begin();
    std::vector<CKeyPool> result;
    WalletBatch batch(m_storage.GetDatabase());
    while (it != std::end(*setKeyPool)) {
        const int64_t& index = *(it);
        if (index > keypool_id) break; 
        CKeyPool keypool;
        if (batch.ReadPool(index, keypool)) { 
            m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
        }
        LearnAllRelatedScripts(keypool.vchPubKey);
        batch.ErasePool(index);
        WalletLogPrintf("keypool index %d removed\n", index);
        it = setKeyPool->erase(it);
        result.push_back(std::move(keypool));
    }
    return result;
}
std::vector<CKeyID> GetAffectedKeys(const CScript& spk, const SigningProvider& provider)