Clean temporary RackMultiPart* files using middleware

config/application.rb

@@ -106,6 +106,9 @@ module OpenProject
                           }
 
     config.middleware.use Rack::Attack
+    # Ensure that tempfiles are cleared after request
+    # http://stackoverflow.com/questions/4590229
+    config.middleware.use Rack::TempfileReaper
     config.middleware.use ::ResetCurrentUser
 
     # Custom directories with classes and modules you want to be autoloadable.