### Describe the issue
Warning messages are not displayed when running bitcoin-qt 0.14.2 and 0.14.99 with -disablewallet.
It might be better to always display them.

E.g. on MainNet the "This is a pre-release test build - use at your own risk - do not use for mining or merchant applications" is lost
![image](https://user-images.githubusercontent.com/3296421/29109760-853e5394-7ce4-11e7-8f05-bfcd66ada471.png)
![image](https://user-images.githubusercontent.com/3296421/29109806-adf6e67a-7ce4-11e7-8564-8883c44656ad.png)

On TestNet also the "Warning: unknown new rules activated (versionbit 28)" is missed
![image](https://user-images.githubusercontent.com/3296421/29110269-6b24b79e-7ce6-11e7-91e7-823227eaa200.png)
![image](https://user-images.githubusercontent.com/3296421/29110035-9142cf34-7ce5-11e7-8faf-264e805cdaf4.png)

namespace {
const QStringList historyFilter = QStringList()
    << "importprivkey"
    << "importmulti"
    << "sethdseed"
    << "signmessagewithprivkey"
    << "signrawtransaction"
    << "signrawtransactionwithkey"
    << "walletpassphrase"
    << "walletpassphrasechange"
    << "encryptwallet";
}
/* Object for executing console RPC commands in a separate thread.
*/
class RPCExecutor : public QObject
{
    Q_OBJECT
public:
    explicit RPCExecutor(interfaces::Node& node) : m_node(node) {}
public Q_SLOTS:
    void request(const QString &command, const QString &walletID);
Q_SIGNALS:
    void reply(int category, const QString &command);
private:
    interfaces::Node& m_node;
};
/** Class for handling RPC timers
 * (used for e.g. re-locking the wallet after a timeout)
 */
class QtRPCTimerBase: public QObject, public RPCTimerBase