proper fix to what r2760 is supposed to fix

scrapy/core/scheduler.py

@@ -26,7 +26,7 @@ class Scheduler(object):
         return cls(dupefilter, job_dir(settings), dqclass)
 
     def has_pending_requests(self):
-        return len(self.dqs) or len(self.mqs)
+        return len(self) > 0
 
     def open(self, spider):
         self.spider = spider

scrapy/utils/pqueue.py

@@ -53,6 +53,3 @@ class PriorityQueue(object):
 
     def __len__(self):
         return sum(len(x) for x in self.queues.values()) if self.queues else 0
-
-    def __nonzero__(self):
-        return bool(self.queues)