### 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

{
    std::string label = value.get_str();
    if (label == "*")
        throw JSONRPCError(RPC_WALLET_INVALID_LABEL_NAME, "Invalid label name");
    return label;
}
static UniValue getnewaddress(const JSONRPCRequest& request)
{
    std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
    CWallet* const pwallet = wallet.get();
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
            RPCHelpMan{"getnewaddress",
                "\nReturns a new Bitcoin address for receiving payments.\n"
                "If 'label' is specified, it is added to the address book \n"
                "so payments received with the address will be associated with 'label'.\n",
                {
                    {"label", RPCArg::Type::STR,  "\"\"", "The label name for the address to be linked to. It can also be set to the empty string \"\" to represent the default label. The label does not need to exist, it will be created if there is no label by the given name."},
                    {"address_type", RPCArg::Type::STR,  "set by -addresstype", "The address type to use. Options are \"legacy\", \"p2sh-segwit\", and \"bech32\"."},
                },
                RPCResult{
            "\"address\"    (string) The new bitcoin address\n"
                },
                RPCExamples{
                    HelpExampleCli("getnewaddress", "")
            + HelpExampleRpc("getnewaddress", "")
                },
            }.Check(request);