Fix for retry_over_time when no errback specified
Fix for retry_over_time when no errback specified

bmbouter/kombu,numb3r3/kombu,xujun10110/kombu,ZoranPavlovic/kombu,iris-edu-int/kombu,Elastica/kombu,romank0/kombu,romank0/kombu,bmbouter/kombu,daevaorn/kombu,numb3r3/kombu,mverrilli/kombu,tkanemoto/kombu,cce/kombu,jindongh/kombu,cce/kombu,andresriancho/kombu,Elastica/kombu,xujun10110/kombu,alex/kombu,celery/kombu,iris-edu-int/kombu,alex/kombu,ZoranPavlovic/kombu,mverrilli/kombu,andresriancho/kombu,tkanemoto/kombu,jindongh/kombu,daevaorn/kombu,urbn/kombu