NethServer 6.7 02/16 updates & Let's Encrypt

HI @giacomo @filippo_carletti, on Clean NEW installation.
[root@mail etc]# /usr/libexec/nethserver/letsencrypt-certs -v
/usr/sbin/letsencrypt.sh --cron --config /etc/letsencrypt.sh/config.sh -d mail.dnis.pp.ua -d dnis.pp.ua
# INFO: Using main config file /etc/letsencrypt.sh/config.sh
+ Generating account key...
+ Registering account key with letsencrypt...
ERROR: WELLKNOWN directory doesn't exist, please create /etc/letsencrypt.sh/.acme-challenges and set appropriate permissions.