add -i (Perl version): color header to match the C version
Both versions of `add -i` indent non-flat lists by five spaces. However
when using color the C version prints these spaces after the ANSI color
codes whereas the Perl version prints them before the color codes.
Change the Perl version to match the C version to allow for introducing
a test that verifies that both versions produce the exact same output.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>