mycoursesmenulimit setting issue

[Jeremy Hopkins]

When mycoursesmenulimit is set to 0 it should show all courses in the "My Courses" drop down list.

This does not seem to work, setting to 0 actually results in the number of listed courses being limited to 20.

[Manoj Solanki]

Fix #777. Use isset instead of empty to test for value of 0 in variable.

→ <<cset be05ad5c2446>>