Should honour query is_404 property 

Currently loads the defined template even when ```$query->is_404 == true```
@tcrsavage rather than check `$wp_query->query` if there is a query, can you check the `$this-> get_wp_query_args()` instead as that's really what we want to look at. Also `$wp_query->is_404()` (call it as a method for better layer of abstraction).