You have one or more scripts in
/etc/update-motd.d/*. You can remove them or do:
sudo touch /var/lib/update-motd/disabled
This script executes lists of scripts in lexical order, concatenating
and writing the output to /var/lib/motd, which is usually a symbolic
link to /etc/motd.
Users and/or packages should add symbolic links to /etc/update-motd.d/,
/etc/update-motd.d/hourly, /etc/update-motd.d/daily, /etc/update-
motd.d/weekly, /etc/update-motd.d/monthly, prepended with a two-digit
number to define the displayed order, as obeyed by run-parts(8).
Separate cron jobs will run update-motd every 10 minutes, hourly,
daily, weekly, and monthly. Each of execution of update-motd will run
the scripts in the corresponding /etc/update-motd.d/ directory. The
output of each script will be written and cached in /var/run/update-
motd/*, retaining the number and name of the script executed, to pre‐
serve the ordering of the output in /etc/motd. After execution of the
current set of scripts, all files in /var/run/update-motd/ will be con‐
catenated with /etc/motd.tail and written to /etc/motd.
The update-motd script will not execute if the file /var/lib/update-
motd/disabled exists. One can override this using the --force option.
To permanently enable/disable update-motd, use:
$ sudo update-motd --enable
$ sudo update-motd --disable
If you're using X11/Gnome, I don't think you want to disable console-kit-daemon since it's a part of the login process. If you're not, then I'd just disable X.