Fixed User Can't Optout Of Alert Emails

When a user unchecks the alert preference for "and receive email notifications" and leaves the corresponding action (ex: Tag you in a photo) checked, then a record for _email (ex: sonnb_xengallery_photo_tag_email) is added to xf_user_alert_optout. This is as expected.

However, the bug appears if the user also unchecks the action (ex: Tag you in a photo). In this case, the sonnb_xengallery_photo_tag_email record is removed and instead replaced with sonnb_xengallery_photo_tag. This applies for all actions. It seems that if the user unchecks both the alert action and the email preference, that they continue to receive emails even though they have opted out.

On a very busy site this is generating thousands of unwanted emails.