Add error message if the category haven't got products

templates/default/category.html

@@ -18,6 +18,7 @@
         {$product_page={$smarty.get.page|default:1}}
         {$product_order={$smarty.get.order|default:'alpha'}}
         <article class="col-main {$smarty.get.mode|default:"grid"}" role="main">
+            {ifloop rel="product_list"}
                 {include file="includes/toolbar.html" toolbar="top" limit=$limit order=$product_order}
                 <div id="category-products">
                     <div class="products-content">
@@ -29,6 +30,12 @@
                     </div>
                 </div><!-- /#category-products -->
                 {include file="includes/toolbar.html" toolbar="bottom"}
+            {/ifloop}
+            {elseloop rel="product_list"}
+                <div class="address-warning">
+                    No products
+                </div>
+            {/elseloop}
         </article>
 
         <aside class="col-left" role="complementary" itemscope itemtype="http://schema.org/WPSideBar">