### 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

break;
            case feebumper::Result::WALLET_ERROR:
                throw JSONRPCError(RPC_WALLET_ERROR, errors[0]);
                break;
            default:
                throw JSONRPCError(RPC_MISC_ERROR, errors[0]);
                break;
        }
    }
    
    if (!feebumper::SignTransaction(*pwallet, mtx)) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Can't sign transaction.");
    }
    
    uint256 txid;
    if (feebumper::CommitTransaction(*pwallet, hash, std::move(mtx), errors, txid) != feebumper::Result::OK) {
        throw JSONRPCError(RPC_WALLET_ERROR, errors[0]);
    }
    UniValue result(UniValue::VOBJ);
    result.pushKV("txid", txid.GetHex());
    result.pushKV("origfee", ValueFromAmount(old_fee));
    result.pushKV("fee", ValueFromAmount(new_fee));
    UniValue result_errors(UniValue::VARR);
    for (const std::string& error : errors) {
        result_errors.push_back(error);
    }
    result.pushKV("errors", result_errors);
    return result;
}
UniValue rescanblockchain(const JSONRPCRequest& request)