MAAS rack and region controllers poll the status of services every
minute, cluttering the logs with messages like the ones below. This
change turns disables sudo logging for the maas user.
sudo[10061]: maas : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/systemctl status ntp
sudo[10061]: pam_unix(sudo:session): session opened for user root by (uid=0)
sudo[10061]: pam_unix(sudo:session): session closed for user root
Change-Id: I18547c5248cf73743cd8c0f26c471854540936eb