MDVA-222: Port down MAGETWO-50611

Author: isitnikov

app/code/Magento/WebapiSecurity/Model/Plugin/CacheInvalidator.php

@@ -26,22 +26,17 @@ public function __construct(\Magento\Framework\App\Cache\TypeListInterface $cach
      * Invalidate WebApi cache if needed.
      * 
      * @param \Magento\Framework\App\Config\Value $subject
-     * @param \Magento\Framework\App\Config\Value|null $result
-     * @return \Magento\Framework\App\Config\Value|null
+     * @return \Magento\Framework\App\Config\Value
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      */
-    public function afterAfterSave(
-        \Magento\Framework\App\Config\Value $subject,
-        $result
-    ) {
-        if (!is_null($result)) {
-            if ($result->getPath() == \Magento\WebapiSecurity\Model\Plugin\AnonymousResourceSecurity::XML_ALLOW_INSECURE
-                && $result->isValueChanged()
-            ) {
-                $this->cacheTypeList->invalidate(\Magento\Framework\App\Cache\Type\Webapi::TYPE_IDENTIFIER);
-            }
+    public function afterAfterSave(\Magento\Framework\App\Config\Value $subject)
+    {
+        if ($subject->getPath() == \Magento\WebapiSecurity\Model\Plugin\AnonymousResourceSecurity::XML_ALLOW_INSECURE
+            && $subject->isValueChanged()
+        ) {
+            $this->cacheTypeList->invalidate(\Magento\Framework\App\Cache\Type\Webapi::TYPE_IDENTIFIER);
         }
 
-        return $result;
+        return $subject;
     }
 }