Merge pull request #121 from red56/master

backporting fix to rails/rails#8119 from

Author: rafaelfranca

lib/sprockets/rails/legacy_asset_url_helper.rb

@@ -21,8 +21,7 @@ def asset_path(source, options = {})
           source = compute_asset_path(source, options)
         end
 
-        relative_url_root = (defined?(config.relative_url_root) && config.relative_url_root) ||
-          (respond_to?(:request) && request.try(:script_name))
+        relative_url_root = defined?(config.relative_url_root) && config.relative_url_root
         if relative_url_root
           source = "#{relative_url_root}#{source}" unless source.starts_with?("#{relative_url_root}/")
         end