[#30472] Cannot cancel Download Tracks in com_banners

Joomla! Tracker Item [#30472](http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=30472&start=0)

# Executive summary

In the back-end, Banners, Track, Export the Cancel button doesn't work. Moreover, once you click on Download the modal doesn't automatically close.

# Issue analysis

The Javascript on the modal is referencing the no longer used Squeezebox. Since we are now using Bootstrap's modal we merely need to update the Javascript to use $(element).modal.close();