systemd-login: Avoid a crash on container
    
    On containers dbus could be not running.
    In this case dbus.system_connection is NULL and calling
    dbus_connection_close on it will cause a crash.
    This happens also under Gitlab CI.
    
    Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
    Acked-by: Victor Toso <victortoso@redhat.com>
    (cherry picked from commit 5654f4d2f90f95efd1f0ca70b438a3ab81022d15)
    
    patch_name: 0003-systemd-login-Avoid-a-crash-on-container.patch
    present_in_specfile: true
    location_in_specfile: 3
    squash_commits: true