### 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

UniValue entry(UniValue::VOBJ);
            if (involvesWatchonly || (::IsMine(*pwallet, r.destination) & ISMINE_WATCH_ONLY)) {
                entry.pushKV("involvesWatchonly", true);
            }
            MaybePushAddress(entry, r.destination);
            if (wtx.IsCoinBase())
            {
                if (wtx.GetDepthInMainChain(locked_chain) < 1)
                    entry.pushKV("category", "orphan");
                else if (wtx.IsImmatureCoinBase(locked_chain))
                    entry.pushKV("category", "immature");
                else
                    entry.pushKV("category", "generate");
            }
            else
            {
                entry.pushKV("category", "receive");
            }
            entry.pushKV("amount", ValueFromAmount(r.amount));
            if (pwallet->mapAddressBook.count(r.destination)) {
                entry.pushKV("label", label);
            }
            entry.pushKV("vout", r.vout);
            if (fLong)
                WalletTxToJSON(pwallet->chain(), locked_chain, wtx, entry);
            ret.push_back(entry);
        }
    }
}
static const std::string TransactionDescriptionString()