Cufon JS breaks when selector field empty

If the selector field on admin/settings/cufon but a font is selected then a JS error will be triggered to the likes of:

"Uncaught TypeError: Cannot read property 'fontStyle' of null"

This seems to also break all other javascript that would run on the page too (at least when js is aggregated). Attached is a patch that corrects the issues by removing all empty selectors prior to the "drupal_add_js(array('cufonSelectors' => $selectors), 'setting');" command.

Cheers,
Scott