App crashes when try to purchase with no Google account on device

[intrications]

         E  com.niveales.testsnowboards2014 fatal error : An error occured while executing doInBackground()
                    E  java.lang.RuntimeException: An error occured while executing doInBackground()
                    E      at android.os.AsyncTask$3.done(AsyncTask.java:299)
                    E      at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
                    E      at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
                    E      at java.util.concurrent.FutureTask.run(FutureTask.java:239)
                    E      at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
                    E      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
                    E      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
                    E      at java.lang.Thread.run(Thread.java:838)
                    E  Caused by: java.lang.NullPointerException
                    E      at com.librelio.products.ui.ProductsBillingActivity$5$1.doInBackground(ProductsBillingActivity.java:424)
                    E      at com.librelio.products.ui.ProductsBillingActivity$5$1.doInBackground(ProductsBillingActivity.java:391)
                    E      at android.os.AsyncTask$2.call(AsyncTask.java:287)
                    E      at java.util.concurrent.FutureTask.run(FutureTask.java:234)
                    E      ... 4 more