Cleanup: skip sending unused JSON

This data, when returned by this endpoint, is never used in the js
client[1].  It also causes server-side warnings!
A little bit of progress for LibriVox#153.

[1]: https://github.com/LibriVox/librivox-catalog/blob/master/public_html/js/private/validator/index.js#L29

application/controllers/private/Validator.php

@@ -324,7 +324,7 @@ function copy_project_files()
 			$this->librivox_id3tag->_update_section($section->id, array('file_name' => $file_name, 'playtime' => $playtime));
 		}
 
-		$this->ajax_output(array('message' => 'Files copied.', 'tags' => $tag_data, 'full_tags' => $fullid3_tags), TRUE);
+		$this->ajax_output(array('message' => 'Files copied.'), TRUE);
 	}
 
 	function get_file_tags()