Upgrade to 2.2.1-RC (alibaba#9741)

Merge pull request alibaba#9707 from alibaba/develop

Merge develop into master to release 2.2.0

Upgrade to 2.2.0-beta. (alibaba#9413)

Merge pull request alibaba#9335 from alibaba/develop

Upgrade to 2.1.2

Merge pull request alibaba#8902 from alibaba/develop

Upgrade 2.1.1

Merge pull request alibaba#8900 from alibaba/v1.x-develop

Upgrade to 1.4.4

Merge pull request alibaba#8279 from alibaba/develop

Upgrade to 2.1.0

fix newline (alibaba#8064)

[ISSUE alibaba#7593]修复集群模式使用内置数据库配置中心配置文件丢失 (alibaba#7612)

[ISSUE#7519] Optimize configuration history deletion logic (alibaba#7531

)

* remove config history .for#7519

* remove config history .for#7519

* remove config history .for#7519

* update style