Invalid characters for a wallet name, e.g. `bitcoin-qt -wallet=你好` used to result in an error like this

<img width="494" alt="schermafbeelding 2018-07-24 om 17 46 37" src="https://user-images.githubusercontent.com/10217/43150553-7bdf598a-8f6a-11e8-8972-44c311a57e56.png">

But now it just crashes:

<img width="509" alt="schermafbeelding 2018-07-24 om 17 43 26" src="https://user-images.githubusercontent.com/10217/43150605-9cf32192-8f6a-11e8-9333-87d074c8dd35.png">

I didn't do a `git bisect`, but it broke somewhere this year :-)
if (nDepth == 0 && pcoin->mapValue.count("replaces_txid")) {
            safeTx = false;
        }
        
        
        
        
        
        
        
        
        if (nDepth == 0 && pcoin->mapValue.count("replaced_by_txid")) {
            safeTx = false;
        }
        if (fOnlySafe && !safeTx) {
            continue;
        }
        if (nDepth < nMinDepth || nDepth > nMaxDepth)
            continue;
        for (unsigned int i = 0; i < pcoin->tx->vout.size(); i++) {