Fix morning questionnaire notification

It will not beep, not flash, not vibrate (since by default it appears at
5am).

Also removed the custom sound for notifications, which was only working
when not asked to beep. I think this would be better as a full feature
where the user can choose his own notification sound, rather than a
half-baked one.
I'll try reactivate it to get it to work for all probes (except MQ of course)