Removing backslashes in meta elements so that the final page code is …

…valid (without warnings) according to the HTML specification.

Some meta elements are already without the slash but some with, so let it be completely nice in this file.

templates/_partials/head.tpl

@@ -58,11 +58,11 @@
   {/block}
 
   {block name='head_open_graph'}
-    <meta property="og:title" content="{$page.meta.title}" />
-    <meta property="og:description" content="{$page.meta.description}" />
-    <meta property="og:url" content="{$urls.current_url}" />
-    <meta property="og:site_name" content="{$shop.name}" />
-    {if !isset($product) && $page.page_name != 'product'}<meta property="og:type" content="website" />{/if}
+    <meta property="og:title" content="{$page.meta.title}">
+    <meta property="og:description" content="{$page.meta.description}">
+    <meta property="og:url" content="{$urls.current_url}">
+    <meta property="og:site_name" content="{$shop.name}">
+    {if !isset($product) && $page.page_name != 'product'}<meta property="og:type" content="website">{/if}
   {/block}  
 {/block}