Repeat hours of zero for courses

Project information
Project: 
Project version: 
4.x-4.2.3
Category: 
feature request
Priority: 
normal
Status: 
active
Description: 

As per a received email, make it so that the "Repeat" hours of a course can be set to zero, since the min hours can be set to zero.

Such would mean that the course can be taken once and not repeated at all, basically.

Right now the form submission interprets this as "blank" and sets the repeat hours to the default value of the max hours.