[SAC] jef added to sudo group on secure

[Sandro Santilli]

FYI: I've added Jurgen Fisher in the "sudo" group
on the "secure" machine. He wanted to kill "apticron"
for what he thinks is excessive noise done by mail.

>From apt-cache show apticron:

 Simple tool to mail about pending package updates. Apticron is a simple
 script which sends daily emails about pending package updates such as
 security updates, properly handling packages on hold both by dselect
 and aptitude.

In this specific case sysadmin alias is getting daily mail about
an invalid signature for an apt repository:

 W: GPG error: http://archive.debian.org squeeze Release:
 The following signatures were invalid:
 KEYEXPIRED 1520281423 KEYEXPIRED 1501892461

--strk;