Update Sentinel to 1.8.6 in Spring Cloud Alibaba 2021.x branch

[steverao]

我们鼓励使用英文，如果不能直接使用，可以使用翻译软件，您仍旧可以保留中文原文。
We recommend using English. If you are non-native English speaker, you can use the translation software.

Which Component
eg. Sentinel,

Is your feature request related to a problem? Please describe.
We are prepared to release a new version of Spring Cloud Alibaba in 2021.x branch, we are plan to update some components.

Describe the solution you'd like
A clear and concise description of what you want to happen.
Update Sentinel to 1.8.6 in Spring Cloud Alibaba 2021.x branch, and test the reliability.

[yuluo-yx]

I'm trying to update, please give me some time!

[yuluo-yx]

I'm done with the update, please see #3070

[steverao]

We updated it and close it.