Merge branch 'sw-24973/5.6/fix-hreflang-on-error-page' into '5.6'

SW-24973 - Fix broken hreflang tags on 404 page

See merge request shopware/5/product/shopware!276

engine/Shopware/Plugins/Default/Frontend/Seo/Bootstrap.php

@@ -147,7 +147,7 @@ public function onPostDispatch(Enlight_Controller_ActionEventArgs $args)
             $view->assign('SeoMetaDescription', $metaDescription);
         }
 
-        if ($this->get('config')->get('hrefLangEnabled')) {
+        if (!$request->getParam('error_handler') && $this->get('config')->get('hrefLangEnabled')) {
             $context = $this->get('shopware_storefront.context_service')->getShopContext();
 
             $params = $request->getParams();