New Permission: View Forum (#4866).

Patch by Felix Schäfer.

git-svn-id: http://svn.redmine.org/redmine/trunk@16637 e93f8b46-1217-0410-a6f0-8f06a7374b81

db/migrate/20170419144536_add_view_messages_to_all_existing_roles.rb

@@ -0,0 +1,9 @@
+class AddViewMessagesToAllExistingRoles < ActiveRecord::Migration
+  def up
+    Role.all.each { |role| role.add_permission! :view_messages }
+  end
+
+  def down
+    # nothing to revert
+  end
+end