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);
            std::map<uint256, int>::iterator mi = mapRequestCount.find(hash);
            if (mi != mapRequestCount.end())
                (*mi).second++;
        }
    }
    void GetScriptForMining(std::shared_ptr<CReserveScript> &script);
    
    unsigned int GetKeyPoolSize()
    {
        AssertLockHeld(cs_wallet); 
        return setInternalKeyPool.size() + setExternalKeyPool.size();
    }
    
    bool SetMinVersion(enum WalletFeature, CWalletDB* pwalletdbIn = nullptr, bool fExplicit = false);
    
    bool SetMaxVersion(int nVersion);
    
    int GetVersion() { LOCK(cs_wallet); return nWalletVersion; }