ignore a group question ref to unrecognized xpath
ignore a group question ref to unrecognized xpath

and log the error for debugging

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