only add to error

Author: ylebre

src/Server.php

@@ -44,8 +44,8 @@ final public function respondToAccessTokenRequest(Request $request) : Response
             $response = $authorizationServer->respondToAccessTokenRequest($request, $response);
         } catch (OAuthServerException $serverException) {
             $response = $this->createOauthServerExceptionResponse($response, $serverException);
+            $response = $this->addIssuerToResponse($response);
         }
-        $response = $this->addIssuerToResponse($response);
         return $response;
     }