gitweb: Fix test of highlighting support in t9500 The commit 7ce896b (Enable highlight executable path as a configuration option, 2010-09-21) forgot to update t9500 test. While at it, describe highlight test better. Signed-off-by: Jakub Narebski <jnareb@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>