Description
The Cache_promote plugin currently uses the URL when using the LRU policy. It would be better to use the cachekey, as that is actually going to be the index later.
This would make any cachekey modifications also work for the promotion algorithm. For instance, if a domain has a (randomish) query string that gets removed for the cachekey, using the URL in the LRU would effectively never allow it to be promoted to cache, whereas the cachekey would.