Since a9d34933 ("Merge branch 'fm/fetch-raw-sha1'", 2015-06-01) we
allow to fetch by an object name when the other side accepts such a
request, but we never updated the documentation to match.
Signed-off-by: Junio C Hamano <gitster@pobox.com> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>