fix: accept 409 from the MyEP contact form endpoint

public/typo3conf/ext/ep_products/Classes/MyEP/ApiClient.php

@@ -100,7 +100,9 @@ class ApiClient implements LoggerAwareInterface
             'json' => $addressData,
         ]);
 
-        $this->assertStatusCode($response, [Response::HTTP_OK, Response::HTTP_CREATED, Response::HTTP_ACCEPTED, Response::HTTP_NO_CONTENT], 'POST', 'contactform');
+        // A conflict means the address is already registered, which is the normal answer to a
+        // resubmitted contact form and not worth reporting.
+        $this->assertStatusCode($response, [Response::HTTP_OK, Response::HTTP_CREATED, Response::HTTP_ACCEPTED, Response::HTTP_NO_CONTENT, Response::HTTP_CONFLICT], 'POST', 'contactform');
     }
 
     /**