The git_feed() method was not setting a `Status` header unless it was
responding to an If-Modified-Since request with `304 Not Modified`.
Now, when it is serving successful responses, it sets status to `200
OK`.
Signed-off-by: W Trevor King <wking@drexel.edu> Acked-by: Jakub Narebski <jnareb@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>