Superfluous subscription message with Notifications Autosubscribe module

Using the Notifications Autosubscribe module causes the following message to appear whenever a comment is posted by a user already subscribed to the topic:

A duplicated subscription has been found and updated

To reproduce:

1. add a new node, or find an existing one;
2. subscribe to that node;
3. add a comment to the node;
4. add more comments to taste, message is repeated every time;

At best this message is superfluous, at worst it will cause user confusion. Off topic: great module, thanks for your hard work. :)