Built against `master` branch 801dd40666d1e6009920ad3ff755c7bb993b2a62:

If I have no wallet.dat file and run:

    bitcoind -usehd=0

A new wallet.dat file is created and an HD seed is assigned.

I see an error message in the source:

    "Error loading %s: You can't disable HD on an already existing HD wallet or create new non-HD wallets."

but that doesn't get shown because `fFirstRun` is true, and so the code which checks for `-usehd` values doesn't run.

If it's no longer possible to create non-HD wallets, specifying -usehd=0 when creating a wallet should be an error, and not get silently ignored.
{
    unsigned int nTimeSmart = wtx.nTimeReceived;
    if (!wtx.hashUnset()) {
        if (mapBlockIndex.count(wtx.hashBlock)) {
            int64_t latestNow = wtx.nTimeReceived;
            int64_t latestEntry = 0;
            
            int64_t latestTolerated = latestNow + 300;
            const TxItems& txOrdered = wtxOrdered;
            for (auto it = txOrdered.rbegin(); it != txOrdered.rend(); ++it) {
                CWalletTx* const pwtx = it->second.first;
                if (pwtx == &wtx) {
                    continue;
                }
                CAccountingEntry* const pacentry = it->second.second;
                int64_t nSmartTime;
                if (pwtx) {
                    nSmartTime = pwtx->nTimeSmart;
                    if (!nSmartTime) {
                        nSmartTime = pwtx->nTimeReceived;
                    }
                } else {
                    nSmartTime = pacentry->nTime;
                }
                if (nSmartTime <= latestTolerated) {
                    latestEntry = nSmartTime;
                    if (nSmartTime > latestNow) {
                        latestNow = nSmartTime;
                    }