fix rebuildstaging merge output
fix rebuildstaging merge output

was autostaging => foo, is now
origin/master => foo

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