[Issue tracker] - No email notification when added to watchers

[charliehenrib]

Describe the bug
When added to watching for an issue, I don't receive an email notification.

To Reproduce
Steps to reproduce the behavior (attach screenshots if applicable):
Make sure you have two accounts. With the first account, create an issue and add your second account as a watcher.

What did you expect to happen?
A clear and concise description of what you expected to happen.
You should receive an email saying you have been added as a watcher to an issue.