Fixed error in celery, during startup the export task.
Fixed error in celery, during startup the export task.

dimagi/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,puttarajubr/commcare-hq,qedsoftware/commcare-hq,puttarajubr/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,qedsoftware/commcare-hq,puttarajubr/commcare-hq,SEL-Columbia/commcare-hq,puttarajubr/commcare-hq,SEL-Columbia/commcare-hq,dimagi/commcare-hq,SEL-Columbia/commcare-hq,dimagi/commcare-hq