### 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

}.Check(request);
    LOCK(pwallet->cs_wallet);
    UniValue ret(UniValue::VOBJ);
    CTxDestination dest = DecodeDestination(request.params[0].get_str());
    
    if (!IsValidDestination(dest)) {
        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid address");
    }
    std::string currentAddress = EncodeDestination(dest);
    ret.pushKV("address", currentAddress);
    CScript scriptPubKey = GetScriptForDestination(dest);
    ret.pushKV("scriptPubKey", HexStr(scriptPubKey.begin(), scriptPubKey.end()));
    isminetype mine = IsMine(*pwallet, dest);
    ret.pushKV("ismine", bool(mine & ISMINE_SPENDABLE));
    bool solvable = IsSolvable(*pwallet, scriptPubKey);
    ret.pushKV("solvable", solvable);
    if (solvable) {
       ret.pushKV("desc", InferDescriptor(scriptPubKey, *pwallet)->ToString());
    }
    ret.pushKV("iswatchonly", bool(mine & ISMINE_WATCH_ONLY));
    UniValue detail = DescribeWalletAddress(pwallet, dest);
    ret.pushKVs(detail);
    if (pwallet->mapAddressBook.count(dest)) {
        ret.pushKV("label", pwallet->mapAddressBook[dest].name);
    }
    ret.pushKV("ischange", pwallet->IsChange(scriptPubKey));
    const CKeyMetadata* meta = nullptr;
    CKeyID key_id = GetKeyForDestination(*pwallet, dest);
    if (!key_id.IsNull()) {
        auto it = pwallet->mapKeyMetadata.find(key_id);