Fix gitbook link

Author: sb2nov

_posts/2014-04-20-mac-os-x-setup-guide.md

@@ -6,7 +6,7 @@ excerpt: Guide on creating a productive developer environment on MacOS.
 redirect_from: /2014/04/20/mac-os-x-setup-guide/
 ---
 
-I recently updated the Mac OS X setup guide I maintain to an interactive [Gitbook](http://www.gitbook.io/). You can reference it [here (Mac OS X Setup Guide)](/mac-setup).
+I recently updated the Mac OS X setup guide I maintain to an interactive [Gitbook](https://www.gitbook.com/). You can reference it [here (Mac OS X Setup Guide)](/mac-setup).
 
 <img src="/images/blog/2014-04/mac-gitbook.png" alt="Screenshot" style="width: 80%; margin-left:10%; margin-right:10%; margin-top:20px; margin-bottom:20px;"/>