If git-fetch-pack was called with out any refspec, it would ask the server
for funny refs. That cannot work, since the funny refs are not marked
as OUR_REF by upload-pack, which just exits with an error.
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>