fix 404

[chenglu]

Xihan，下次更新文档的时候麻烦抽空把这俩 404 解决一下呗，谢谢啦 ;-)

404 - https://tf.wiki/en/deployment/en_savedmodel
(found at https://tf.wiki/en/deployment/serving.html)

404 - https://tf.wiki/py-modindex.html
(found at https://tf.wiki/)