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
}
```
if (!GetPubKey(keypool.vchPubKey.GetID(), pk)) {
            throw std::runtime_error(std::string(__func__) + ": unknown key in key pool");
        }
        
        if (use_split_keypool && keypool.fInternal != fReturningInternal) {
            throw std::runtime_error(std::string(__func__) + ": keypool entry misclassified");
        }
        if (!keypool.vchPubKey.IsValid()) {
            throw std::runtime_error(std::string(__func__) + ": keypool entry invalid");
        }
        assert(m_index_to_reserved_key.count(nIndex) == 0);
        m_index_to_reserved_key[nIndex] = keypool.vchPubKey.GetID();
        m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
        WalletLogPrintf("keypool reserve %d\n", nIndex);
    }
    NotifyCanGetAddressesChanged();
    return true;
}
void LegacyScriptPubKeyMan::LearnRelatedScripts(const CPubKey& key, OutputType type)
{
    assert(type != OutputType::BECH32M);
    if (key.IsCompressed() && (type == OutputType::P2SH_SEGWIT || type == OutputType::BECH32)) {
        CTxDestination witdest = WitnessV0KeyHash(key.GetID());
        CScript witprog = GetScriptForDestination(witdest);
        
        assert(IsSolvable(*this, witprog));
        AddCScript(witprog);
    }
}
void LegacyScriptPubKeyMan::LearnAllRelatedScripts(const CPubKey& key)