### 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

},
            true, true);
        if (options.exists("confTarget") && (options.exists("totalFee") || options.exists("fee_rate"))) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "confTarget can't be set with totalFee or fee_rate. Please provide either a confirmation target in blocks for automatic fee estimation, or an explicit fee rate.");
        } else if (options.exists("fee_rate") && options.exists("totalFee")) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "fee_rate can't be set along with totalFee.");
        } else if (options.exists("confTarget")) { 
            coin_control.m_confirm_target = ParseConfirmTarget(options["confTarget"], pwallet->chain().estimateMaxBlocks());
        } else if (options.exists("totalFee")) {
            if (!pwallet->chain().rpcEnableDeprecated("totalFee")) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "totalFee argument has been deprecated and will be removed in 0.20. Please use -deprecatedrpc=totalFee to continue using this argument until removal.");
            }
            totalFee = options["totalFee"].get_int64();
            if (totalFee <= 0) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid totalFee %s (must be greater than 0)", FormatMoney(totalFee)));
            }
        } else if (options.exists("fee_rate")) {
            CFeeRate fee_rate(AmountFromValue(options["fee_rate"]));
            if (fee_rate <= CFeeRate(0)) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid fee_rate %s (must be greater than 0)", fee_rate.ToString()));
            }
            coin_control.m_feerate = fee_rate;
        }
        if (options.exists("replaceable")) {
            coin_control.m_signal_bip125_rbf = options["replaceable"].get_bool();
        }
        if (options.exists("estimate_mode")) {
            if (!FeeModeFromString(options["estimate_mode"].get_str(), coin_control.m_fee_mode)) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid estimate_mode parameter");
            }