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 :-)
LOCK2(cs_main, cs_wallet);
    for (const CTransactionRef& ptx : pblock->vtx) {
        SyncTransaction(ptx);
    }
}
void CWallet::BlockUntilSyncedToCurrentChain() {
    AssertLockNotHeld(cs_main);
    AssertLockNotHeld(cs_wallet);
    {
        
        
        
        
        
        LOCK(cs_main);
        const CBlockIndex* initialChainTip = chainActive.Tip();
        if (m_last_block_processed && m_last_block_processed->GetAncestor(initialChainTip->nHeight) == initialChainTip) {
            return;
        }
    }
    
    
    
    SyncWithValidationInterfaceQueue();
}
isminetype CWallet::IsMine(const CTxIn &txin) const