If one calls `fundrawtransaction`, the change address will be retrieved from the keypool, though, this key/address will always be returned to the pool, leading to the problem that the next `getnewaddress()` call will restult in the same key/address.

Either we remove the auto-change-address (users would need to call `getrawchangeaddress` first [current best practice anyway]) or we add a call to keep/mark a specific key/address as change (after one have sent the funded raw transaction).

Reported by @NicolasDorier on IRC.
"\nArguments:\n"
            "1. nrequired        (numeric, required) The number of required signatures out of the n keys or addresses.\n"
            "2. \"keys\"         (string, required) A json array of bitcoin addresses or hex-encoded public keys\n"
            "     [\n"
            "       \"address\"  (string) bitcoin address or hex-encoded public key\n"
            "       ...,\n"
            "     ]\n"
            "3. \"account\"      (string, optional) DEPRECATED. An account to assign the addresses to.\n"
            "\nResult:\n"
            "\"address\"         (string) A bitcoin address associated with the keys.\n"
            "\nExamples:\n"
            "\nAdd a multisig address from 2 addresses\n"
            + HelpExampleCli("addmultisigaddress", "2 \"[\\\"16sSauSf5pF2UkUwvKGq4qjNRzBZYqgEL5\\\",\\\"171sgjn4YtPu27adkKGrdDwzRTxnRkBfKV\\\"]\"") +
            "\nAs json rpc call\n"
            + HelpExampleRpc("addmultisigaddress", "2, \"[\\\"16sSauSf5pF2UkUwvKGq4qjNRzBZYqgEL5\\\",\\\"171sgjn4YtPu27adkKGrdDwzRTxnRkBfKV\\\"]\"")
        ;
        throw runtime_error(msg);
    }
    LOCK2(cs_main, pwalletMain->cs_wallet);
    string strAccount;
    if (request.params.size() > 2)
        strAccount = AccountFromValue(request.params[2]);
    
    CScript inner = _createmultisig_redeemScript(request.params);
    CScriptID innerID(inner);
    pwalletMain->AddCScript(inner);
    pwalletMain->SetAddressBook(innerID, strAccount, "send");
    return CBitcoinAddress(innerID).ToString();
}
class Witnessifier : public boost::static_visitor<bool>