more explictly force a zero
more explictly force a zero

wasn't caught before because couchdbkit removes None values from dynamic properties

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