only send issue follow emails when more than one person on project

I'm the only person on most of my projects and I don't like getting emails every time I update/create my own cases. However, if I do add another person to the project at a later time, I will want to get email updates, without having to go into every case and check "follow issue updates".

I propose the option to configure issue tracker emails to only be sent if there is more than one person on a project.