Remove link to outdated release process

Author: julienrf

blog/_posts/2017-10-16-fourth-dotty-milestone-release.md

@@ -18,7 +18,7 @@ You can learn more about Dotty on our [website](https://dotty.epfl.ch).
 
 <!--more-->
 
-This is our fourth scheduled release according to our [6-week release schedule](https://dotty.epfl.ch/docs/contributing/procedures/release.html).
+This is our fourth scheduled release according to our 6-week release schedule.
 The [previous technology preview](/blog/2017/09/07/third-dotty-milestone-release.html) improved
 stability and reliability.