### 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

} else if (options.exists("confTarget")) { 
            coin_control.m_confirm_target = ParseConfirmTarget(options["confTarget"]);
        } else if (options.exists("totalFee")) {
            totalFee = options["totalFee"].get_int64();
            if (totalFee <= 0) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid totalFee %s (must be greater than 0)", FormatMoney(totalFee)));
            }
        }
        if (options.exists("replaceable")) {
            coin_control.signalRbf = options["replaceable"].get_bool();
        }
        if (options.exists("estimate_mode")) {
            if (!FeeModeFromString(options["estimate_mode"].get_str(), coin_control.m_fee_mode)) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid estimate_mode parameter");
            }
        }
    }
    LOCK2(cs_main, pwallet->cs_wallet);
    EnsureWalletIsUnlocked(pwallet);
    CFeeBumper feeBump(pwallet, hash, coin_control, totalFee);
    BumpFeeResult res = feeBump.getResult();
    if (res != BumpFeeResult::OK)
    {
        switch(res) {
            case BumpFeeResult::INVALID_ADDRESS_OR_KEY:
                throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, feeBump.getErrors()[0]);
                break;
            case BumpFeeResult::INVALID_REQUEST:
                throw JSONRPCError(RPC_INVALID_REQUEST, feeBump.getErrors()[0]);
                break;