fix celery error logging, https://www.pivotaltracker.com/story/show/16914437
fix celery error logging, https://www.pivotaltracker.com/story/show/16914437

wevoice/wesub,eloquence/unisubs,ujdhesa/unisubs,ReachingOut/unisubs,norayr/unisubs,ofer43211/unisubs,ofer43211/unisubs,ReachingOut/unisubs,ofer43211/unisubs,eloquence/unisubs,eloquence/unisubs,wevoice/wesub,ofer43211/unisubs,ujdhesa/unisubs,wevoice/wesub,pculture/unisubs,wevoice/wesub,ujdhesa/unisubs,ReachingOut/unisubs,ReachingOut/unisubs,pculture/unisubs,eloquence/unisubs,norayr/unisubs,norayr/unisubs,norayr/unisubs,pculture/unisubs,ujdhesa/unisubs,pculture/unisubs