Avoid crash when adding new translations

Paranoia is activated on translation classes by reflection, this is
making Rails to load translation classes before to execute migration
that adds the new column.

With this extra check Rails will not execute this code until translation
table has this column created.

app/models/concerns/globalizable.rb

@@ -17,7 +17,7 @@ module Globalizable
       self.read_attribute(:description).try :html_safe
     end
 
-    if self.paranoid?
+    if self.paranoid? && translation_class.attribute_names.include?("hidden_at")
       translation_class.send :acts_as_paranoid, column: :hidden_at
     end
   end