am 978959e6: Do not vibrate in vibrate mode if ringtone is silent

* commit '978959e6199410419792e89fcea16413f56aeb12':
  Do not vibrate in vibrate mode if ringtone is silent
diff --git a/src/com/android/email/NotificationController.java b/src/com/android/email/NotificationController.java
index 2331f5a..1dc2149 100644
--- a/src/com/android/email/NotificationController.java
+++ b/src/com/android/email/NotificationController.java
@@ -677,7 +677,7 @@
             defaults |= Notification.DEFAULT_VIBRATE;
         }
 
-        builder.setSound((ringtoneUri == null) ? null : Uri.parse(ringtoneUri))
+        builder.setSound(TextUtils.isEmpty(ringtoneUri) ? null : Uri.parse(ringtoneUri))
             .setDefaults(defaults);
     }