you'll need also to modify the first bit
into
############################
# Qmail logfile preprocessor
############################
.....
/bin/cat \$SRC /var/log/qmail/current | /usr/local/bin/tai64nlocal | /usr/bin/perl /usr/local/awstats/tools/maillogconvert.pl standard | /bin/grep -v ' alias-localdelivery-'
with
/bin/cat \$SRC /var/log/qmail/current | /usr/local/bin/tai64nlocal | /usr/bin/perl /usr/bin/maillogconvert.pl standard | /bin/grep -v ' alias-localdelivery-'