0047750: check if email in test is already sent

[eeliabosco]

When a test has 'Notification' enabled in the finishing settings and the time limit expires, the test owner receives a large number of duplicate email notifications instead of just one.
With this pr, it is checked whether the email has already been sent.

[kergomard]

Thank you for the PR @eeliabosco .

Could you please create an issue for this in Mantis and describe the problem more precisely there. Please see the Contribution Guidelines.

This fix has the look and feel of a work around and would thus not be the right solution, but we first need to really understand the issue before we can start figuring that out.

Best,
@kergomard

[kergomard]

Ahhh, sorry, found the issue (please link it in the comment): https://mantis.ilias.de/view.php?id=47750

[kergomard]

So, this actually confirms my suspicions: Why are we performing the finish tasks on every call? What does trigger a call to it "approximately one per second". I think we should figure that out before moving on with a fix.

If you are willing to iterate on this, this would be appreciated otherwise I would close this PR and look at the issue as soon as I/we have the resources.

Thanks again and best,
@kergomard