### 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

LOCK(pwallet->cs_wallet);
    if (!pwallet->CanGetAddresses()) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Error: This wallet has no available keys");
    }
    
    std::string label;
    if (!request.params[0].isNull())
        label = LabelFromValue(request.params[0]);
    OutputType output_type = pwallet->m_default_address_type;
    if (!request.params[1].isNull()) {
        if (!ParseOutputType(request.params[1].get_str(), output_type)) {
            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Unknown address type '%s'", request.params[1].get_str()));
        }
    }
    CTxDestination dest;
    std::string error;
    if (!pwallet->GetNewDestination(output_type, label, dest, error)) {
        throw JSONRPCError(RPC_WALLET_KEYPOOL_RAN_OUT, error);
    }
    return EncodeDestination(dest);
}
static UniValue getrawchangeaddress(const JSONRPCRequest& request)
{
    std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
    CWallet* const pwallet = wallet.get();
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
            RPCHelpMan{"getrawchangeaddress",
                "\nReturns a new Bitcoin address, for receiving change.\n"