BibIndex: regression tests fix for itemcount index

* Adds setUp method for BibIndexItemCountIndexTest
  to initialize the tests.

Signed-off-by: Grzegorz Szpura <grzegorz.szpura@cern.ch>
BibIndex: fix for affected indexes tests

* Removes regression tests issues
  for tests concerning affected indexes.

Signed-off-by: Grzegorz Szpura <grzegorz.szpura@cern.ch>