Change idmap_add_id() to add both ID_TYPE_UID and ID_TYPE_GID entries
to an existing lxc_conf, not just an ID_TYPE_UID entry, so as to work
lxc-destroy with unprivileged containers on recent kernel.
Signed-off-by: TAMUKI Shoichi <tamuki@linet.gr.jp>
Acked-by: KATOH Yasufumi <karma@jazz.email.ne.jp>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>