Merge branch 'fix-ci-link-on-project-page' into 'master'

Fix 500 when showing project page and there's no CI project present

This fixes 500 when:
1. GitLabCiService is active
2. There's no project in ci_projects table


See merge request !1338

app/models/project.rb

@@ -428,7 +428,7 @@ class Project < ActiveRecord::Base
   end
 
   def gitlab_ci?
-    gitlab_ci_service && gitlab_ci_service.active
+    gitlab_ci_service && gitlab_ci_service.active && gitlab_ci_project.present?
   end
 
   def ci_services