When I run `scantxoutset` via RPC using big range (e.g. 10000) on XPUB, the progress report indicator (`scantxoutset status`) reports 100% at start (while the keys are being derived). This is most probably the result of the previous operation. The progress is only reset to zero when the actual scan starts. I would expect the progress is set to zero before the keys are being derived.

Output of periodic calls to `scantxoutset status` while performing long operation.

```
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 0 }
{ progress: 3 }
{ progress: 6 }
{ progress: 9 }
{ progress: 12 }
{ progress: 15 }
{ progress: 17 }
{ progress: 20 }
{ progress: 23 }
{ progress: 26 }
{ progress: 29 }
{ progress: 32 }
{ progress: 35 }
{ progress: 37 }
{ progress: 40 }
{ progress: 43 }
{ progress: 46 }
{ progress: 49 }
{ progress: 51 }
{ progress: 54 }
{ progress: 57 }
{ progress: 60 }
{ progress: 63 }
{ progress: 66 }
{ progress: 68 }
{ progress: 71 }
{ progress: 74 }
{ progress: 77 }
{ progress: 80 }
{ progress: 82 }
{ progress: 85 }
{ progress: 88 }
{ progress: 91 }
{ progress: 94 }
{ progress: 97 }
{ progress: 100 }
```
const CBlockIndex* pindex;
    int blockcount = 30 * 24 * 60 * 60 / Params().GetConsensus().nPowTargetSpacing; 
    if (request.params[1].isNull()) {
        LOCK(cs_main);
        pindex = chainman.ActiveChain().Tip();
    } else {
        uint256 hash(ParseHashV(request.params[1], "blockhash"));
        LOCK(cs_main);
        pindex = chainman.m_blockman.LookupBlockIndex(hash);
        if (!pindex) {
            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
        }
        if (!chainman.ActiveChain().Contains(pindex)) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Block is not in main chain");
        }
    }
    CHECK_NONFATAL(pindex != nullptr);
    if (request.params[0].isNull()) {
        blockcount = std::max(0, std::min(blockcount, pindex->nHeight - 1));
    } else {
        blockcount = request.params[0].get_int();
        if (blockcount < 0 || (blockcount > 0 && blockcount >= pindex->nHeight)) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid block count: should be between 0 and the block's height - 1");
        }
    }
    const CBlockIndex* pindexPast = pindex->GetAncestor(pindex->nHeight - blockcount);
    int nTimeDiff = pindex->GetMedianTimePast() - pindexPast->GetMedianTimePast();
    int nTxDiff = pindex->nChainTx - pindexPast->nChainTx;
    UniValue ret(UniValue::VOBJ);
    ret.pushKV("time", (int64_t)pindex->nTime);