Redmine

First thanks for the great work and the new major version.

I just updated from 2.6.1 to 3.0.0. My environment looks like the following:

Environment:
  Redmine version                3.0.0.stable
  Ruby version                   1.9.3-p484 (2013-11-22) [x86_64-linux]
  Rails version                  4.2.0
  Environment                    production
  Database adapter               PostgreSQL

When I navigate to the repository tab of a projects settings where only one committer contributed to the repository and click on "Users" I get the following error:

Started GET "/repositories/8/committers" for xxx at 2015-03-03 12:02:24 +0100
Processing by RepositoriesController#committers as HTML
  Parameters: {"id"=>"8"}
  Current user: xxx (id=1)
Completed 500 Internal Server Error in 18ms

NoMethodError (undefined method `compact!' for #<User::ActiveRecord_Relation:0x007f8d1586a480>):
  app/controllers/repositories_controller.rb:98:in `committers'

This does not happen if the repository I want to configure has more than one contributor.