Course element "Task": Confirmation email after submitting revised document

Confirmation email in course element "Task"

How to reproduce:

1. Open a course with a task. A student submits the required document.
   => OK: Student gets a confirmation email (see screenshot).

1. The couch asks for a revision.
2. The student submits a revised version of the document.
   => NOK: Student does not get any confirmation email.

Expected behaviour:

Student should get a similar confirmation email when submitting a revised document.