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 }
```
Coin coin;
    unsigned int iter{0};
    while (pcursor->Valid()) {
        if (iter % 5000 == 0) node.rpc_interruption_point();
        ++iter;
        if (pcursor->GetKey(key) && pcursor->GetValue(coin)) {
            afile << key;
            afile << coin;
        }
        pcursor->Next();
    }
    afile.fclose();
    UniValue result(UniValue::VOBJ);
    result.pushKV("coins_written", stats.coins_count);
    result.pushKV("base_hash", tip->GetBlockHash().ToString());
    result.pushKV("base_height", tip->nHeight);
    return result;
}
void RegisterBlockchainRPCCommands(CRPCTable &t)
{
static const CRPCCommand commands[] =
{ 
  
    { "blockchain",         &getblockchaininfo,                  },
    { "blockchain",         &getchaintxstats,                    },
    { "blockchain",         &getblockstats,                      },
    { "blockchain",         &getbestblockhash,                   },
    { "blockchain",         &getblockcount,                      },
    { "blockchain",         &getblock,                           },
    { "blockchain",         &getblockhash,                       },