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).
{
    nTime = GetTime();
    vchPubKey = vchPubKeyIn;
    fInternal = internalIn;
    m_pre_split = false;
}
int CWalletTx::GetDepthInMainChain() const
{
    assert(pwallet != nullptr);
    AssertLockHeld(pwallet->cs_wallet);
    if (isUnconfirmed() || isAbandoned()) return 0;
    return (pwallet->GetLastBlockHeight() - m_confirm.block_height + 1) * (isConflicted() ? -1 : 1);
}
int CWalletTx::GetBlocksToMaturity() const
{
    if (!IsCoinBase())
        return 0;
    int chain_depth = GetDepthInMainChain();
    assert(chain_depth >= 0); 
    return std::max(0, (COINBASE_MATURITY+1) - chain_depth);
}
bool CWalletTx::IsImmatureCoinBase() const
{
    
    return GetBlocksToMaturity() > 0;
}
std::vector<OutputGroup> CWallet::GroupOutputs(const std::vector<COutput>& outputs, bool single_coin) const {