### 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

{
    CWallet * const pwallet = GetWalletForJSONRPCRequest(request);
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
    if (request.fHelp || request.params.size() < 1 || request.params.size() > 2)
        throw std::runtime_error(
            "getreceivedbyaccount \"account\" ( minconf )\n"
            "\nDEPRECATED. Returns the total amount received by addresses with <account> in transactions with at least [minconf] confirmations.\n"
            "\nArguments:\n"
            "1. \"account\"      (string, required) The selected account, may be the default account using \"\".\n"
            "2. minconf          (numeric, optional, default=1) Only include transactions confirmed at least this many times.\n"
            "\nResult:\n"
            "amount              (numeric) The total amount in " + CURRENCY_UNIT + " received for this account.\n"
            "\nExamples:\n"
            "\nAmount received by the default account with at least 1 confirmation\n"
            + HelpExampleCli("getreceivedbyaccount", "\"\"") +
            "\nAmount received at the tabby account including unconfirmed amounts with zero confirmations\n"
            + HelpExampleCli("getreceivedbyaccount", "\"tabby\" 0") +
            "\nThe amount with at least 6 confirmations\n"
            + HelpExampleCli("getreceivedbyaccount", "\"tabby\" 6") +
            "\nAs a json rpc call\n"
            + HelpExampleRpc("getreceivedbyaccount", "\"tabby\", 6")
        );
    ObserveSafeMode();
    LOCK2(cs_main, pwallet->cs_wallet);