Bug 16397 - Unable to delete audio alerts

Bug 16397 - Unable to delete audio alerts

This patch corrects a JavaScript error which has arisen due to the
jQuery upgrade. This should have been included in Bug 16321.

To test, apply the patch and go to Administration -> Audio alerts.

- In the list of existing audio alerts, check one or more checkboxes.
  The "Delete selected" button should become enabled.
- Uncheck all checkboxes and check that the "Delete selected" button is
  now disabled.
- Confirm that deletions are completed correctly.

Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>