Fix regression causing "Start a New Course" button to not display

Carson reported (https://rt.sfu.ca/Ticket/Display.html?id=263353) that the Start a New Course button is no longer showing up. The `if` statement to check `show_user_create_course_button` is not needed for our button.

The code now matches 2fbc47803891ace6d5d4c2a9cd0e2229f9479693