Bug: https://gitlab.com/gitlab-org/gitlab-ce/issues/2857

Index: gitlab/Gemfile
===================================================================
--- gitlab.orig/Gemfile
+++ gitlab/Gemfile
@@ -187,7 +187,7 @@ gem "loofah", "~> 2.0.3"
 gem "rack-attack", '~> 4.3.1'
 
 # Ace editor
-gem 'ace-rails-ap', '~> 2.0.1'
+gem 'ace-rails-ap', '~> 3.0.3'
 
 # Keyboard shortcuts
 gem 'mousetrap-rails', '~> 1.4.6'