`ScanForWalletTransactions()` has the following comment about its return value:

```
 * Returns null if scan was successful. Otherwise, if a complete rescan was not
 * possible (due to pruning or corruption), returns pointer to the most recent
 * block that could not be scanned.
```

This is not strictly true. If `abortrescan` is called, then `ScanForWalletTransactions()` will return `nullptr`, even though the scan wasn't successful to the tip.

This in turn causes a minor bug in `importmulti`, where the call doesn't return the correct error and warning about potentially not finding transactions if `abortrescan` was called.

I think the correct fix is for `ScanForWalletTransactions()` to inform the caller that the rescan was aborted.
if (wtxIn.tx->HasWitness() && !wtx.tx->HasWitness()) {
            wtx.SetTx(wtxIn.tx);
            fUpdated = true;
        }
    }
    
    WalletLogPrintf("AddToWallet %s  %s%s\n", wtxIn.GetHash().ToString(), (fInsertedNew ? "new" : ""), (fUpdated ? "update" : ""));
    
    if (fInsertedNew || fUpdated)
        if (!batch.WriteTx(wtx))
            return false;
    
    wtx.MarkDirty();
    
    NotifyTransactionChanged(this, hash, fInsertedNew ? CT_NEW : CT_UPDATED);
    
    std::string strCmd = gArgs.GetArg("-walletnotify", "");
    if (!strCmd.empty())
    {
        boost::replace_all(strCmd, "%s", wtxIn.GetHash().GetHex());
        std::thread t(runCommand, strCmd);
        t.detach(); 
    }
    return true;
}
void CWallet::LoadToWallet(const CWalletTx& wtxIn)