NoMethodError (undefined method `shared_runners_enabled' when trying to enable CI for a project

Problem observed after upgrading from Gitlab CE v8.1.4 to v8.2.0

Steps to reproduce

• go to a project that does not have CI enabled
• "settings"
• "ci settings" or "runners"

Backtrace

NoMethodError (undefined method `shared_runners_enabled' for #<ApplicationSetting:0x00000006036898>):
  app/models/project.rb:794:in `ensure_gitlab_ci_project'
  app/controllers/projects/application_controller.rb:36:in `ci_project'

May be related to #3556 (closed)