[IMP] website_sale: show categories on mobile device

Task 20251

addons/website_sale/views/templates.xml

@@ -264,7 +264,7 @@
             </ul>
         </xpath>
         <xpath expr="//div[@id='products_grid_before']" position="attributes">
-            <attribute name="class">col-md-3 col-sm-4 hidden-xs</attribute>
+            <attribute name="class">col-md-3 col-sm-4 col-xs-12</attribute>
         </xpath>
         <xpath expr="//div[@id='products_grid']" position="attributes">
             <attribute name="class">col-md-9 col-sm-8</attribute>