[GitLab] can't modify frozen ActiveSupport::HashWithIndifferentAccess - again

[Torsten Zuehlsdorff]

Hello,

after finishing all dependencies and sidework on the port for GitLab 
8.3.x i stumpled accross the same error like before:

$ rake gitlab:setup RAILS_ENV=production
[..]
== Seed from /usr/local/www/gitlab/db/fixtures/production/001_admin.rb
rake aborted!
can't modify frozen ActiveSupport::HashWithIndifferentAccess
(eval):9:in `block (2 levels) in run_file'
/usr/local/www/gitlab/lib/tasks/gitlab/setup.rake:20:in `setup_db'
/usr/local/www/gitlab/lib/tasks/gitlab/setup.rake:4:in `block (2 levels) 
in <top (required)>'
Tasks: TOP => db:seed_fu
(See full trace by running task with --trace)

This is a little bit frustrating, because this is exactly the error 
which drove me to resurrect RAILS 4.1. With Rails 4.1 the error did not 
occur. :D

My ruby is not good enough do fix it. Can somebody help?

Greetings,
Torsten