[PATCH] fetch.c: Do not build object ref lists

The fetch code does not need object ref lists; by disabling them we
can save some time and memory.

Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Junio C Hamano <junkio@cox.net>

fetch.c

@@ -206,6 +206,7 @@ int pull(char *target)
 	int fd = -1;
 
 	save_commit_buffer = 0;
+	track_object_refs = 0;
 	if (write_ref && current_ref) {
 		fd = lock_ref_sha1(write_ref, current_ref);
 		if (fd < 0)