Merge pull request #2802 from nextcloud/intentMaybeNull

intent may be null on service restart

src/main/java/com/owncloud/android/files/services/FileDownloader.java

@@ -178,7 +178,7 @@ public class FileDownloader extends Service
 
         startForeground(FOREGROUND_SERVICE_ID, mNotification);
 
-        if (!intent.hasExtra(EXTRA_ACCOUNT) || !intent.hasExtra(EXTRA_FILE)) {
+        if (intent == null || !intent.hasExtra(EXTRA_ACCOUNT) || !intent.hasExtra(EXTRA_FILE)) {
             Log_OC.e(TAG, "Not enough information provided in intent");
             return START_NOT_STICKY;
         } else {