Fixes build

celery/tests/concurrency/test_threads.py

@@ -20,31 +20,31 @@ class test_TaskPool(AppCase):
 
         with mask_modules('threadpool'):
             with self.assertRaises(ImportError):
-                TaskPool()
+                TaskPool(app=self.app)
 
     def test_with_threadpool(self):
         with mock_module('threadpool'):
-            x = TaskPool()
+            x = TaskPool(app=self.app)
             self.assertTrue(x.ThreadPool)
             self.assertTrue(x.WorkRequest)
 
     def test_on_start(self):
         with mock_module('threadpool'):
-            x = TaskPool()
+            x = TaskPool(app=self.app)
             x.on_start()
             self.assertTrue(x._pool)
             self.assertIsInstance(x._pool.workRequests, NullDict)
 
     def test_on_stop(self):
         with mock_module('threadpool'):
-            x = TaskPool()
+            x = TaskPool(app=self.app)
             x.on_start()
             x.on_stop()
             x._pool.dismissWorkers.assert_called_with(x.limit, do_join=True)
 
     def test_on_apply(self):
         with mock_module('threadpool'):
-            x = TaskPool()
+            x = TaskPool(app=self.app)
             x.on_start()
             callback = Mock()
             accept_callback = Mock()