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.
{
    LOCK(cs_wallet);
    if (!memonly && !CWalletDB(*dbw).WriteHDChain(chain))
        throw std::runtime_error(std::string(__func__) + ": writing chain failed");
    hdChain = chain;
    return true;
}
bool CWallet::IsHDEnabled() const
{
    return !hdChain.masterKeyID.IsNull();
}
int64_t CWalletTx::GetTxTime() const
{
    int64_t n = nTimeSmart;
    return n ? n : nTimeReceived;
}
int CWalletTx::GetRequestCount() const
{
    
    int nRequests = -1;
    {
        LOCK(pwallet->cs_wallet);
        if (IsCoinBase())
        {