Page is automatically watched by user if they add an attachment to the page even with the "autowatch" setting disabled.

This cause a user to automatically watch a page when they add an attachment to the page. This bug cause unnecessary notication that causes major spam in the user mailbox.

Step to replicate

1. Go to User Profile >> Settings >> Email and disable the autowatch
2. Add an attachment to an existing page

Observed behaviour

User who added the attachment are now watching the page.

Extra Note
This issue does not occur in Confluence 5.6.6 and below.