Don't duplicate users in Issue#assignable_users. From r4240

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@4241 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/issue.rb

@@ -392,7 +392,7 @@ class Issue < ActiveRecord::Base
   def assignable_users
     users = project.assignable_users
     users << author if author
-    users.sort
+    users.uniq.sort
   end
   
   # Versions that the issue can be assigned to