offer-muc-dbus-tube: factor out bob_in_tube()
offer-muc-dbus-tube: factor out bob_in_tube()

jku/telepathy-gabble,Ziemin/telepathy-gabble,community-ssu/telepathy-gabble,Ziemin/telepathy-gabble,community-ssu/telepathy-gabble,Ziemin/telepathy-gabble,Ziemin/telepathy-gabble,community-ssu/telepathy-gabble,mlundblad/telepathy-gabble,jku/telepathy-gabble,mlundblad/telepathy-gabble,jku/telepathy-gabble,mlundblad/telepathy-gabble,community-ssu/telepathy-gabble