Redirection des urls avec un slash à la fin

common/config/main.php

 return [
     'vendorPath' => dirname(dirname(__DIR__)) . '/vendor',
     'on beforeRequest' => function () {
-        $url = Yii::$app->request->getAbsoluteUrl();
-        if (!empty($url) && substr($url, -1) == '/') {
-            $url = substr($url, 0, strlen($url) - 1);
-            Yii::$app->getResponse()->redirect($url, 301);
-            Yii::$app->end();
+        if(method_exists(Yii::$app->request, 'getAbsoluteUrl')) {
+            $url = Yii::$app->request->getAbsoluteUrl();
+            if (!empty($url) && substr($url, -1) == '/') {
+                $url = substr($url, 0, strlen($url) - 1);
+                Yii::$app->getResponse()->redirect($url, 301);
+                Yii::$app->end();
+            }
         }
     },
     'components' => [