systemd: Add Also between sockets

systemd: Add Also between sockets

This results in all sockets for a service being enabled when a
single one of them is.

The -tcp and -tls sockets are intentionally excluded, because
enabling them should require explicit action on the
administrator's part; moreover, disabling them should not result
in the local sockets being disabled too.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>