t/t0006: specify timezone as EST5 not EST to comply with POSIX POSIX requires that both the timezone "standard" and "offset" be specified in the TZ environment variable. This causes a problem on IRIX which does not understand the timezone 'EST'. Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil> Signed-off-by: Junio C Hamano <gitster@pobox.com>