Fix Ruby China links

Author: huacnlee

en/downloads/mirrors/index.md

@@ -48,7 +48,7 @@ Please try to use a mirror that is near you.
 [mirror-http-nl]: http://www.xs4all.nl/~hipster/lib/mirror/ruby/
 [mirror-http-at]: http://gd.tuwien.ac.at/languages/ruby/
 [mirror-http-cn1]: https://ruby.taobao.org/mirrors/ruby/
-[mirror-http-cn2]: https://cache.ruby-china.org/pub/ruby/
+[mirror-http-cn2]: https://cache.ruby-china.com/pub/ruby/
 [mirror-ftp-jp-ring-shibaura-it]: ftp://ring.shibaura-it.ac.jp/pub/lang/ruby/
 [mirror-ftp-jp-ring-u-toyama]: ftp://ring.u-toyama.ac.jp/pub/lang/ruby/
 [mirror-ftp-jp-ring-airnet]: ftp://ring.airnet.ne.jp/pub/lang/ruby/

zh_cn/community/index.md

@@ -41,4 +41,4 @@ Ruby 的一般信息
 [3]: http://rubycentral.org/
 [4]: http://dmoz.org/Computers/Programming/Languages/Ruby/
 [5]: http://dmoz.org/Computers/Programming/Languages/Ruby/Software/Rails/
-[ruby-china]: http://ruby-china.org
+[ruby-china]: https://ruby-china.org

zh_cn/news/_posts/2011-12-29-ruby-china.md

@@ -26,5 +26,5 @@ GitHub 项目地址：
 
 
 
-[1]: http://www.ruby-china.org
-[2]: http://github.com/huacnlee/ruby-china
+[1]: https://ruby-china.org
+[2]: https://github.com/ruby-china/homeland