tab character violates intendation while scanning a plain scalar

  1. Summary: GitLab does not start after upgrade from 7.9 stable to 7.10 stable
  2. Steps to reproduce: upgrade like it is described here
  3. Expected behavior: GitLab should start
  4. Observed behavior see above
  5. Relevant logs and/or screenshots: (<unknown>): found a tab character that violate intendation while scanning a plain scalar at line 133 column 40
  6. Output of checks 
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true
rake aborted!
Psych::SyntaxError: (<unknown>): found a tab character that violate intendation while scanning a plain scalar at line 133 column 40
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/settingslogic-2.0.9/lib/settingslogic.rb:103:in `initialize'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/settingslogic-2.0.9/lib/settingslogic.rb:60:in `new'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/settingslogic-2.0.9/lib/settingslogic.rb:60:in `instance'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/settingslogic-2.0.9/lib/settingslogic.rb:37:in `[]'
/home/git/gitlab/config/initializers/1_settings.rb:63:in `<top (required)>'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:241:in `load'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:241:in `block in load'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:232:in `load_dependency'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:241:in `load'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/engine.rb:648:in `block in load_config_initializer'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.9/lib/active_support/notifications.rb:161:in `instrument'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/engine.rb:647:in `load_config_initializer'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/engine.rb:612:in `block (2 levels) in <class:Engine>'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/engine.rb:611:in `each'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/engine.rb:611:in `block in <class:Engine>'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/initializable.rb:30:in `instance_exec'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/initializable.rb:30:in `run'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/initializable.rb:55:in `block in run_initializers'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/initializable.rb:44:in `each'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/initializable.rb:44:in `tsort_each_child'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/initializable.rb:54:in `run_initializers'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/application.rb:300:in `initialize!'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/railtie.rb:194:in `public_send'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/railtie.rb:194:in `method_missing'
/home/git/gitlab/config/environment.rb:5:in `<top (required)>'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:247:in `require'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:247:in `block in require'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:232:in `load_dependency'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:247:in `require'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/application.rb:276:in `require_environment!'
/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/railties-4.1.9/lib/rails/application.rb:405:in `block in run_tasks_blocks'
Tasks: TOP => gitlab:check => gitlab:env:check => environment
(See full trace by running task with --trace)
* Version of GitLab you are running: `7-10-stable`
* Add the last commit SHA-1 of the GitLab version you used to replicate the issue: a651951723269ff414fb1047e83b5075a5733533
* Describe your setup: like in install.md
  1. Possible fixes: