Bug 29679: Remove redundant divider element from reports menu

Bug 29679: Remove redundant divider element from reports menu

The SQL report batch operations dropdown menu has divider list items
which add a border between sections (Bibliographic records, item
records, etc.). This element is redundant because the sections have
"headers" which also add a border.

This patch removes them.

To test, apply the patch and run an SQL report which will return results
that trigger the batch modification menu:

SELECT biblio.biblionumber , biblio.title, items.itemnumber,
items.itemcallnumber, items.barcode, borrowers.firstname,
borrowers.surname, borrowers.borrowernumber, borrowers.cardnumber
FROM issues
LEFT JOIN borrowers ON borrowers.borrowernumber=issues.borrowernumber
LEFT JOIN items ON issues.itemnumber=items.itemnumber
LEFT JOIN biblio ON items.biblionumber=biblio.biblionumber
ORDER BY RAND()

There should be no double border in the menu.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>