Incoming call notifications stay visible for unanswered call

Incoming call notifications appear as expected with the Accept and Reject buttons when Jami is ringing. However, these notifications stay forever visible for unanswered calls unless the user clicks on the notification. It is obviously impossible to accept or reject a incoming call that has already been missed after Jami stopped ringing but it is still confusing.

The expected behavior is that notifications disappear once Jami has stopped ringing (the incoming call times out).

Note: it is possible to reproduce this bug both for Jami and SIP calls.