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.
#include "wallet/wallet.h"
#include "base58.h"
#include "checkpoints.h"
#include "chain.h"
#include "wallet/coincontrol.h"
#include "consensus/consensus.h"
#include "consensus/validation.h"
#include "fs.h"
#include "init.h"
#include "key.h"
#include "keystore.h"
#include "validation.h"
#include "net.h"
#include "policy/fees.h"
#include "policy/policy.h"
#include "policy/rbf.h"
#include "primitives/block.h"
#include "primitives/transaction.h"
#include "script/script.h"
#include "script/sign.h"
#include "scheduler.h"
#include "timedata.h"
#include "txmempool.h"
#include "util.h"
#include "ui_interface.h"
#include "utilmoneystr.h"
#include "wallet/fees.h"