[Dovecot] Valid config for lda_mailbox_autosubscribe with dovecot 1.2?

[Joan]

Hi,

Due to some reasons I've to support both dovecot 1.2 and dovecot 2.x, and I
just found that the -s parameter I used to autosubscribe to sieve folders
doesn't exist anymore in dovecot 2.x
The problem arises because (AFAIK) in postfix's master.cf you can only
specify one configuration, and I used to have this:

dovecot   unix  -       n       n       -       -       pipe
  flags=DRhu user=vmail argv=/usr/lib/dovecot/deliver -f ${sender} -d
${recipient} -s


Is there any way to make the config compatible for both versions, achieving
the autosubscribe and not crashing dovecot?