Triggered when profile cover is deleted.

<?php
function my_component_init(){
		ossn_register_callback('delete', 'profile:cover:photo', 'my_component_cb');
}
function my_component_cb($callback, $type, $params){
		// $params['photo'] contains the (array) of Files Object
}
ossn_register_callback('ossn', 'init', 'my_component_init');