Bug 36760: Use 'strong' for 'Assignee' label

This patch simply add the 'strong' class to the assignee label in the
catalog concerns display ticket modal.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>

koha-tmpl/intranet-tmpl/prog/js/modals/display_ticket.js

@@ -21,7 +21,7 @@ $(document).ready(function () {
         display += '<div class="list-group-item">';
         if (assignee) {
             display +=
-                '<span class="pull-right"><span class="label">' +
+                '<span class="pull-right"><span class="label strong">' +
                 __("Assignee") +
                 "</span>: " +
                 assignee +