LP1913221: Don't display blank course section number in OPAC

LP1913221: Don't display blank course section number in OPAC

To test:

1) Use the Library Settings Editor to turn on the Course Materials
   Module.
2) In Local administration, go to the course reserves list.
3) Add several courses, some with section numbers, others without.
4) In the OPAC, use the Course Search function to search for the courses
   you just added.
5) Notice that the search results page has a place for section numbers,
   whether or not the course has one.
6) Click into some of the courses.  Notice that the course page also
   includes a place for section numbers, whether or not the course has
   one.
7) Apply this patch.
8) Repeat steps 4-6.  Notice that the blank "section number" areas no
   longer appear.

Signed-off-by: Jane Sandberg <sandbej@linnbenton.edu>