change celery result backend

dnscelery.py

@@ -8,12 +8,10 @@ from celery import Celery
 
 HOSTNAME = gethostname()
 AMQP_URI = getenv('AMQP_URI')
-CACHE_URI = getenv('CACHE_URI')
 
 celery = Celery('dnsdriver', broker=AMQP_URI)
 celery.conf.update(
-    CELERY_RESULT_BACKEND='cache',
-    CELERY_CACHE_BACKEND=CACHE_URI,
+    CELERY_RESULT_BACKEND='amqp',
     CELERY_TASK_RESULT_EXPIRES=300,
     CELERY_QUEUES=(
         Queue(HOSTNAME + '.dns', Exchange(