Hi, I implement Ringcaptcha
```
controller.sendCaptchaCodeToNumber(this, phoneNumber, RingcaptchaService.SMS, new RingcaptchaHandler() { @Override
public void onSuccess(RingcaptchaResponse ringcaptchaResponse) {
}
@Override
public void onError(Exception e) {
ALog.d(TAG, e.getMessage());
}
}, BuildConfig.RING_CAPCHA_API_KEY);
When i call `sendCaptchaCodeToNumber` , I received sms has pin, response status"SUCCESS" in log, but response jump in to onError with message"`'android.content.SharedPreferences android.content.Context.getSharedPreferences(java.lang.String, int)' on a null object reference", not onSuccess.
I use gradle to implement Ringcaptcha library. Please let me know what's wrong with this. thanks.