Subsequently we assume that there is only one pack. Currently this is
true only by accident. Pass '-a -d' to repack in order to guarantee that
assumption to hold true.
The prune-packed command is now redundant since repack -d already calls
it.
Signed-off-by: Clemens Buchacher <drizzd@aon.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>