Merge pull request #2865 from Adyen/ECP-8974

[ECP-8974]MOTO payment notifications can't be processed if there is no merchant account set

Author: khushboo-singhvi

Controller/Webhook/Index.php

@@ -213,10 +213,12 @@ private function isAuthorised(array $response)
     {
         // Add CGI support
         $this->fixCgiHttpAuthentication();
+        $merchantAccount = $this->configHelper->getMerchantAccount()
+            ?? $this->configHelper->getMotoMerchantAccounts();
 
         $authResult = $this->notificationReceiver->isAuthenticated(
             $response,
-            $this->configHelper->getMerchantAccount(),
+            $merchantAccount,
             $this->configHelper->getNotificationsUsername(),
             $this->configHelper->getNotificationsPassword()
         );