### Describe the issue

Testing in bitcoin 0.13.0, calling `bitcoin-cli listsinceblock x` is outputting all double-spent transactions that are in the wallet, even those that were double-spent well and truly before x.
### Is the issue reproducible?

Yes
#### List steps to reproduce below:
1.   Create a double-spend send to your wallet (easiest using bip125)
2.   Wait until one confirms, and then wait a few more blocks
3.   Run `bitcoin-cli listsinceblock $(bitcoin-cli getbestblockhash)` and it will output the double spent transaction
### Expected behavior

The double-spent transaction that was conflicted before the block hash should be filtered

CMutableTransaction mtx;
    if (!DecodeHexTx(mtx, request.params[0].get_str(), true)) {
        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
    }
    
    auto locked_chain = pwallet->chain().lock();
    LOCK(pwallet->cs_wallet);
    EnsureWalletIsUnlocked(pwallet);
    
    std::map<COutPoint, Coin> coins;
    for (const CTxIn& txin : mtx.vin) {
        coins[txin.prevout]; 
    }
    pwallet->chain().findCoins(coins);
    
    ParsePrevouts(request.params[1], nullptr, coins);
    return SignTransaction(mtx, pwallet, coins, request.params[2]);
}
static UniValue bumpfee(const JSONRPCRequest& request)
{
    std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
    CWallet* const pwallet = wallet.get();
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp))
        return NullUniValue;
            RPCHelpMan{"bumpfee",
                "\nBumps the fee of an opt-in-RBF transaction T, replacing it with a new transaction B.\n"
                "An opt-in RBF transaction with the given txid must be in the wallet.\n"
                "The command will pay the additional fee by reducing change outputs or adding inputs when necessary. It may add a new change output if one does not already exist.\n"
                "If `totalFee` (DEPRECATED) is given, adding inputs is not supported, so there must be a single change output that is big enough or it will fail.\n"
                "All inputs in the original transaction will be included in the replacement transaction.\n"