git-svn - return original format_svn_date semantics

git-svn - return original format_svn_date semantics

When %z was removed from the strftime call and subsituted with a
local gmt offset calculation, time() was no longer the default for
all time functions as it was with the previous localtime(shift).
This is now corrected so that format_svn_time behaves as it used to.

Signed-off-by: Ben Walton <bwalton@artsci.utoronto.ca>
Acked-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>