Fix mongoid deeply nested polimorphic

Got the commit from github. The roles and sub_roles save.

app/views/admin/infos/_form.html.erb

@@ -13,11 +13,11 @@
 			<tbody>
 			<tr class="list_item">
 			    <td><%= is_new ? (f.text_field :key, {:style => "width:150px"}) : @attribute.key %></td>
-			    <% @site_valid_locales.each do |locale| %>
-			      <td>
-			        <%= text_field_tag "#{@attribute_type}[i18n_variable][#{locale}]", (@i18n_variable[locale] if @i18n_variable), :style => "width:150px" %>
-			      </td>
-			    <% end %>
+					<%= f.fields_for :i18n_variable, (@attribute.new_record? ? @attribute.build_i18n_variable : @attribute.i18n_variable) do |f| %>
+					  <% @site_valid_locales.each do |locale| %>
+					    <td><%= f.text_field locale, :style => "width:150px" %></td>
+					  <% end %>
+					<% end %>
 			  </tr>
 			</tbody>
 		</table>