package./systemd: disable utmp

package./systemd: disable utmp

From wikipedia:

    utmp maintains a full accounting of the current status of the
    system, system boot time (used by uptime), recording user
    logins at which terminals, logouts, system events etc.

This is seldom use, if at all, on an embedded device, and may expose
users' behaviour to others (by observing who logs in from where, for
example).

Forcibly disable support for utmp.

Signed-off-by: Norbert Lange <nolange79@gmail.com>
[yann.morin.1998@free.fr: split off to its own patch]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>