Bug 37838: Fix broken remove button in course reserves

To test:
1) Go to staff client -> Course reserves
2) Create a course or go to an existing course
3) Add reserves to the course (will need at least 21 items to be able to go to a second page of results)
4) Go to the second page of results on the course details page
5) Click the Remove button next to a result
6) Notice how the button just makes the page move to the top
7) Apply patch
8) Repeat steps 1-5
9) Notice how the remove button is working as expected

Sponsored-by: Toi Ohomai Institute of Technology
Signed-off-by: Sam Sowanick <sam.sowanick@corvallisoregon.gov>
Signed-off-by: Laura_Escamilla <laura.escamilla@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit bbd644444f)
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>

koha-tmpl/intranet-tmpl/prog/en/modules/course_reserves/course-details.tt

@@ -342,7 +342,7 @@
                 "autoWidth": false,
             }, table_settings );
 
-            $(".delete_item").on( 'click', function(e){
+            $("#course_reserves_table").on( 'click', " .delete_item", function(e){
                 e.preventDefault();
                 if (confirmDelete(_("Are you sure you want to remove this item from the course?") )) {
                     cr_id = $(this).data('cr-id');