The state of the Attendee Form checkbox is not reset to Turn of Attendee.

[ntthitrinh]

To Reproduce
Steps to reproduce the behaviour:
Step 1. Create a new event with a free ticket or a paid ticket.
Step 2. Add an attendee form but not select a ticket.
Step 3. Save event.
Step 4. Find the event created in step 4.
Step 5. Edit Attendee Form of event created in Step 4
Step 6. Click the button "Delete" in "Choose from existing ticket(s)".

#Expected Result:
After clicking on the "Delete" icon:

1. The state of the Attendee Form checkbox must be reset to Attendee Turn.
2. Organizers can re-add new forms

#Actual result:
After clicking on the "Delete" icon:

1. The state of the Attendee Form checkbox is not reset to Turn of Attendee.
2. Organizer cannot add new Attendee Form

Screenshots

[mariobehling]

Actually this is out of scope. We can come back to this later.