Commit 64edf4b2 cleaned up the initialization of git-archive,
at the cost of 'git-archive --list' now requiring a git repo.
This patch reverts the cleanup and documents the requirement
for this particular dirtyness in a test.
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: NJunio C Hamano <junkio@cox.net>