Bug 14345: broken isbn logic prevents display of idreambooks image

Bug 14345: broken isbn logic prevents display of idreambooks image

TEST PLAN
---------
1) Ensure you have a book that would pull up an idreambooks image
   (e.g. The road to character / David Brooks.)
   -- I imported from the Library of Congress via z39.50
2) Ensure your system preferences for idreambook stuff is set.
3) Ensure you have multiple 020$a's for your book, and
   the first one must just be an ISBN number!
   -- I removed the '(hardcover: acidfree paper)' from the first.
   -- I took the second 020 field and changed 020$z to 020$a
4) Search for that book in OPAC and go to details.
   -- There should be a readometer image, but it will be broken.
   -- Notice the ISBN line has "#############; ..."
      This could also be attained by just putting two semi-colon
      separated ISBN's on the first 020$a.
5) Apply this patch
6) Refresh page
   -- readometer image appears. YAY!
7) run koha qa test tools

NOTE: Only changed test plan, so leaving sign-off on.

Signed-off-by: Nick Clemens <nick@quecheelibrary.org>
Signed-off-by: Jonathan Druart <jonathan.druart@koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>