[4.2] fix bug 'cache paginated query with key'

see problem for example here https://laracasts.com/forum/?p=53-how-to-cache-paginated-query-with-key/0

When we make cached paginate query with cache key 
(like `DB::...->remember($time, $key) ->paginate($count)`). 
There should be two queries (get count and the limited query), and second query does not executes, because it gets from cache.