package/nss-mdns: move hook from post-install to finalize
Both nss-mdns and nss-myhostname patch nsswitch.conf file so it needs to be
done at the final stage to support per-package host/target directories.
[Peter: reword]
Signed-off-by: Vincent Prince <vincent.prince.fr@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>