### Describe the issue

I added a second new wallet2.dat. Now I wanted to encrypt it, but `bitcoin-cli help` does not show the command to do so, I need to use `bitcoin-cli -rpcwallet=wallet2.dat help`. This is very un-intuitive, and bad for a help function.

### Can you reliably reproduce the issue?

1. have an encrypted default wallet
2. add new multi wallet wallet2.dat via config file or cmd line options
3. naive `bitcoin-cli help` does not show command to encrypt second wallet.

### Expected behaviour

All wallet encryption, lock and unlock commands should be shown unconditionally in `bitcoin-cli help`.

The dynamic hiding of some lines is arguably worse than the benefit with multiple wallets.

### Actual behaviour

`bitcoin-cli help` shows only wallet encryption commands appropriate for the default wallet.

### What version of bitcoin-core are you using?

bitcoind 0.15.0.1~dfsg-1
deb http://ppa.launchpad.net/luke-jr/bitcoin-core-bip148-unofficial-builds/ubuntu zesty main

### Machine specs:
- OS: Debian 9.2

"5. \"comment\"       (string, optional) An optional comment, stored in the wallet only.\n"
            "\nResult:\n"
            "true|false           (boolean) true if successful.\n"
            "\nExamples:\n"
            "\nMove 0.01 " + CURRENCY_UNIT + " from the default account to the account named tabby\n"
            + HelpExampleCli("move", "\"\" \"tabby\" 0.01") +
            "\nMove 0.01 " + CURRENCY_UNIT + " timotei to akiko with a comment and funds have 6 confirmations\n"
            + HelpExampleCli("move", "\"timotei\" \"akiko\" 0.01 6 \"happy birthday!\"") +
            "\nAs a json rpc call\n"
            + HelpExampleRpc("move", "\"timotei\", \"akiko\", 0.01, 6, \"happy birthday!\"")
        );
    ObserveSafeMode();
    LOCK2(cs_main, pwallet->cs_wallet);
    std::string strFrom = AccountFromValue(request.params[0]);
    std::string strTo = AccountFromValue(request.params[1]);
    CAmount nAmount = AmountFromValue(request.params[2]);
    if (nAmount <= 0)
        throw JSONRPCError(RPC_TYPE_ERROR, "Invalid amount for send");
    if (!request.params[3].isNull())
        
        (void)request.params[3].get_int();
    std::string strComment;
    if (!request.params[4].isNull())
        strComment = request.params[4].get_str();
    if (!pwallet->AccountMove(strFrom, strTo, nAmount, strComment)) {
        throw JSONRPCError(RPC_DATABASE_ERROR, "database error");
    }
    return true;
}
UniValue sendfrom(const JSONRPCRequest& request)