Opt out of Contributor user limit reached emails

[#1]

Description - Give Admins the ability to turn off the Contributor User Limit Reached emails that are auto generated.

Why is this feature important to you - these emails are unnecessary since the user automatically moves from contributor to light user. We also have dashboard reporting in our instance to monitor this change and don't need additional emails.

How would you like the feature to work - allow the admin to opt out of receiving contributor user limit reached emails.

Current Behaviour - emails are auto generated for each admin user.