OpenProject 3.0.15

The newest patch release for OpenProject (3.0.15) has been released and contains several security and bug fixes.
We advise everyone to update their version of OpenProject.

In addition to updating the rails version to 3.2.20, security fixes regarding sprockets are introduced with 3.0.15.
Furthermore, a bug which prevented the timelines macro from working properly has been fixed (#17010).

For a complete list of changes, please refer to the OpenProject 3.0.15 query.