Bug 27168: Sort most popular by number of issues desc

It seems that there is a weird behavior when the title is used as a
second sort

Test plan:
Turn on OpacTopissue
Make sure the table always displays entries sorted by number of issues
desc

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-topissues.tt

@@ -145,7 +145,7 @@
     <script>
         $(function() {
             $("#topissuest").dataTable($.extend(true, {}, dataTablesDefaults, {
-                "sorting": [ [2, "desc"], [0, "asc"] ],
+                "sorting": [[2, "desc"]],
                 "columnDefs": [
                     { "sortable": false, "searchable": false, 'targets': [ 'NoSort' ] },
                     { "type": "anti-the", "targets" : [ "anti-the" ] },