quick fix for couchapp sync design docs for preindexing.
quick fix for couchapp sync design docs for preindexing.

when there's no changes accessing the <foo>-tmp results in a deleted doc exception. preindex suppresses this exception, but this block doesn't.

just adding a quick trap for the exception here.

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