Opening two of the same wallet (tested in v0.18.0 of bitcoin-qt 64 bit) will cause a database collision, and will crash the program.

`[marshall@likon] {21:21} [~] $ bitcoin-0.18.0/bin/bitcoin-qt `
`terminate called after throwing an instance of 'std::runtime_error'  what():  BerkeleyBatch: Can't open database 8204388-wallet.dat (duplicates fileid 8b1c090000000800e25686350000000000000000 from 1352491-wallet.dat)`
`Aborted (core dumped)`

I have been able to reproduce the issue by importing two of the same wallet (with different filenames).
AssertLockHeld(cs_wallet);
    mapKeyBirth.clear();
    LegacyScriptPubKeyMan* spk_man = GetLegacyScriptPubKeyMan();
    assert(spk_man != nullptr);
    LOCK(spk_man->cs_KeyStore);
    
    for (const auto& entry : spk_man->mapKeyMetadata) {
        if (entry.second.nCreateTime) {
            mapKeyBirth[entry.first] = entry.second.nCreateTime;
        }
    }
    
    const Optional<int> tip_height = locked_chain.getHeight();
    const int max_height = tip_height && *tip_height > 144 ? *tip_height - 144 : 0; 
    std::map<CKeyID, int> mapKeyFirstBlock;
    for (const CKeyID &keyid : spk_man->GetKeys()) {
        if (mapKeyBirth.count(keyid) == 0)
            mapKeyFirstBlock[keyid] = max_height;
    }
    
    if (mapKeyFirstBlock.empty())
        return;
    
    for (const auto& entry : mapWallet) {
        
        const CWalletTx &wtx = entry.second;
        if (Optional<int> height = locked_chain.getBlockHeight(wtx.m_confirm.hashBlock)) {