fix cannot add video issue.
Merge branch 'master' of https://github.com/zhangBenson/zy
Merge branch 'master' of https://github.com/zhangBenson/zy
Merge branch 'master' of https://github.com/zhangBenson/zy
change course blog, help SU check in code
Merge branch 'master' of https://github.com/zhangBenson/zy