I'm sometimes getting an invalid json reply from `getwalletinfo` when rescanning is in progress.

The invalid part is this: `"scanning":{"duration":19,"progress":}}` (no value for `progress`).

I can't reliably reproduce this, but I did manage to run into this 3 times now (once every 10-20 attempts or so).

I'm running v0.20.0 and testing against a regtest instance. This happens while doing a batched `importmulti` of 2000 addresses (none of which have history).
}
        if (wtx.IsImmatureCoinBase())
            continue;
        int nDepth = wtx.GetDepthInMainChain();
        if (nDepth < 0)
            continue;
        
        
        if (nDepth == 0 && !wtx.InMempool())
            continue;
        bool safeTx = IsTrusted(wtx, trusted_parents);
        
        
        
        
        
        
        
        
        
        
        
        
        
        
        
        if (nDepth == 0 && wtx.mapValue.count("replaces_txid")) {
            safeTx = false;
        }