source.list classico per stretch

<code>
root@pubblico1:~# cat /etc/apt/sources.list
deb http://httpredir.debian.org/debian stretch main contrib non-free

deb http://security.debian.org/debian-security stretch/updates main contrib non-free
deb-src http://security.debian.org/debian-security stretch/updates main contrib non-free
</code>