Bug 19042: Add mock IndependentBranches=0 for the other test

Bug 19042: Add mock IndependentBranches=0 for the other test

These tests do not cover correctly getletter, but it is not the goal of
this patch. Superlibrarian behaviour must be tested as well.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit e3dafbfccd06af8fca45fada449e93e3d0616cd6)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
(cherry picked from commit d1b5a9f5bb4a28e86fbd2f3c0ca3127a98d2d4d9)
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>