### 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

bool fValidAddress = ExtractDestination(scriptPubKey, address);
        if (destinations.size() && (!fValidAddress || !destinations.count(address)))
            continue;
        UniValue entry(UniValue::VOBJ);
        entry.push_back(Pair("txid", out.tx->GetHash().GetHex()));
        entry.push_back(Pair("vout", out.i));
        if (fValidAddress) {
            entry.push_back(Pair("address", EncodeDestination(address)));
            if (pwallet->mapAddressBook.count(address)) {
                entry.push_back(Pair("account", pwallet->mapAddressBook[address].name));
            }
            if (scriptPubKey.IsPayToScriptHash()) {
                const CScriptID& hash = boost::get<CScriptID>(address);
                CScript redeemScript;
                if (pwallet->GetCScript(hash, redeemScript)) {
                    entry.push_back(Pair("redeemScript", HexStr(redeemScript.begin(), redeemScript.end())));
                }
            }
        }
        entry.push_back(Pair("scriptPubKey", HexStr(scriptPubKey.begin(), scriptPubKey.end())));
        entry.push_back(Pair("amount", ValueFromAmount(out.tx->tx->vout[out.i].nValue)));
        entry.push_back(Pair("confirmations", out.nDepth));
        entry.push_back(Pair("spendable", out.fSpendable));
        entry.push_back(Pair("solvable", out.fSolvable));
        entry.push_back(Pair("safe", out.fSafe));
        results.push_back(entry);
    }
    return results;
}
UniValue fundrawtransaction(const JSONRPCRequest& request)