Bug: https://gitlab.com/gitlab-org/gitlab-ce/issues/6069

Index: gitlab/Gemfile
===================================================================
--- gitlab.orig/Gemfile
+++ gitlab/Gemfile
@@ -8,7 +8,7 @@ gem 'responders', '~> 2.0'
 
 # Specify a sprockets version due to security issue
 # See https://groups.google.com/forum/#!topic/rubyonrails-security/doAVp0YaTqY
-gem 'sprockets', '~> 2.12.3'
+gem 'sprockets', '~> 3.3.0'
 
 # Default values for AR models
 gem "default_value_for", "~> 3.0.0"