Allow for exclusion of opt out option in notification email

[bfriesenvcc]

We do not want our instructors to be able to opt out, but I see no way to disable it (even if setting optoutmonthssetting to zero months in the settings). I've made changes to the language pack as a workaround (see image) where I've made the optoutarchive text a non-breaking space which, if they happen to click on it shows them a message (see image). Unfortunately, if they do that the course still ends up on the opt out list so I have to check this every now and then.

It would be great if there were an option to exclude the opt out option.