Fix Create Linked Ticket modal on Self Service Asset page

ffe0864 migrated some modals to elevator themes but the Create Linked Ticket modal on the Self Service Asset page was not
migrated as well. This patch fixes the issue.

share/html/SelfService/Asset/Helpers/CreateLinkedTicket

@@ -51,5 +51,17 @@ $Asset
 <%init>
 my $asset = LoadAsset($Asset);
 </%init>
-<& /Asset/Elements/CreateLinkedTicket, AssetObj => $asset &>
+<div class="modal-dialog modal-dialog-centered" role="document">
+  <div class="modal-content">
+    <div class="modal-header">
+      <h5 class="modal-title"><&|/l&>Create Linked Ticket</&></h5>
+      <a href="javascript:void(0)" class="close" data-dismiss="modal" aria-label="Close">
+        <span aria-hidden="true">&times;</span>
+      </a>
+    </div>
+    <div class="modal-body">
+      <& /Asset/Elements/CreateLinkedTicket, AssetObj => $asset &>
+    </div>
+  </div>
+</div>
 % $m->abort;