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.
LOCK2(cs_main, cs_wallet);
    SyncTransaction(ptx);
}
void CWallet::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex *pindex, const std::vector<CTransactionRef>& vtxConflicted) {
    LOCK2(cs_main, cs_wallet);
    
    
    
    
    
    
    
    for (const CTransactionRef& ptx : vtxConflicted) {
        SyncTransaction(ptx);
    }
    for (size_t i = 0; i < pblock->vtx.size(); i++) {
        SyncTransaction(pblock->vtx[i], pindex, i);
    }
}
void CWallet::BlockDisconnected(const std::shared_ptr<const CBlock>& pblock) {
    LOCK2(cs_main, cs_wallet);
    for (const CTransactionRef& ptx : pblock->vtx) {
        SyncTransaction(ptx);
    }
}
isminetype CWallet::IsMine(const CTxIn &txin) const