ipa-replica-manage: remove "last init status" if it's None.
    
    we remove the "last init status" section in the output of
    ipa-replica-manage to avoid confusion and show epoch date
    when status is None
    
    Fixes: https://pagure.io/freeipa/issue/7716
    
    Signed-off-by: German Parente <gparente@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Francois Cami <fcami@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>