roundcube add subject to smtp_log

vi program/steps/mail/func.inc

change:

if ($CONFIG['smtp_log']) {
write_log('sendmail', sprintf("User %s [%s]; Message for %s; %s",
$RCMAIL->user->get_username(),
$_SERVER['REMOTE_ADDR'],
$mailto,
!empty($smtp_response) ? join('; ', $smtp_response) : ''));
}

to:

if ($CONFIG['smtp_log']) {
write_log('sendmail', sprintf("User %s [%s]; Message for %s; Subject: %s %s",
$RCMAIL->user->get_username(),
$_SERVER['REMOTE_ADDR'],
$mailto,
$headers['Subject'],
!empty($smtp_response) ? join('; ', $smtp_response) : ''));
}