Bug 15974: Rancor: Correctly select existing authorized value

Bug 15974: Rancor: Correctly select existing authorized value

Test plan:
  1) Open up a record in Rancor with an itemtype besides the first in
     the list ('BK' in the sample itemtypes).
  2) It will show "Book" instead of the correct itemtype.
  3) Apply patch, reload the page.
  4) The correct itemtype should now show.

NOTE: The scope is only 942$c. This corrects that.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit b01aa596abb91f8679c64e89197fbb2b3d9309cc)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>