Elastic: Fix js error when accessing page jumper input with a Tab key

skins/elastic/ui.js

@@ -2240,6 +2240,7 @@ function rcube_elastic_ui()
                 $(this).data('event', 'mouse');
             })
             .on('keydown', function(e) {
+                if (e.originalEvent) {
                     switch (e.originalEvent.which) {
                     case 13:
                     case 32:
@@ -2252,6 +2253,7 @@ function rcube_elastic_ui()
                         $(this).popover('hide');
                         break;
                     }
+                }
             });
 
         // re-add title attribute removed by bootstrap popover