Theme selection not showing up with Redmine 2.4

[GurvanLd]

I installed plugin with Redmine 2.4.0, but couldn't see the selection window in User preferences menu.
I found following error in logs:

Started GET "/my/account" for 127.0.0.1 at 2014-02-07 16:42:41 +0100
Processing by MyController#account as HTML
  Current user: admin (id=1)
  Rendered users/_mail_notifications.html.erb (105.8ms)
Deface: [WARNING] No :original defined for 'user_ui_theme_preference', you should change its definition to include:

Found related entry at:
spree/deface#105

I solved by applying following to plugin code:

diff --git a/Gemfile b/Gemfile
index e89ad92..1e876ba 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,4 @@
-gem 'deface'
+gem 'deface', '~> 1.0.0'
 
 group :development do
   gem 'diffy'
diff --git a/app/overrides/users/_preferences.rb b/app/overrides/users/_preferences.rb
index a7fb739..97f9bf0 100644
--- a/app/overrides/users/_preferences.rb
+++ b/app/overrides/users/_preferences.rb
@@ -1,5 +1,5 @@
 Deface::Override.new(
     :virtual_path => 'users/_preferences',
     :name => 'user_ui_theme_preference',
-    :insert_before => 'code:contains("end"):last',
+    :insert_before => 'erb:contains("end"):last',
     :text => '
<%= pref_fields.select :ui_theme, Redmine::Themes.themes.collect {|t| [t.name, t.id]}, { :include_blank => true } %>
')