Merge pull request #48764 from steve-hardman/issue-48754-part2

(zh-cn) Update an invalid date in its front matter in blog

Author: k8s-ci-robot

content/zh-cn/blog/_posts/2019-12-09-kubernetes-1.17-release-announcement.md

@@ -1,7 +1,7 @@
 ---
 layout: blog
 title: "Kubernetes 1.17：稳定"
-date: 2019-12-09T13：00：00-08：00
+date: 2019-12-09T13:00:00-08:00
 slug: kubernetes-1-17-release-announcement
 evergreen: true
 ---