Redmine

Hello!

How can I deny access delete files from issues so that only the project manager can delete them and the one who added file.

Thank you!

Environment:
  Redmine version                          2.3.0.stable.11692
  Ruby version                             1.8.7 (x86_64-linux)
  Rails version                            3.2.13
  Environment                              production
  Database adapter                         MySQL