fix: validate exceptions

Author: Jimerson21

SAPb1/SAPException.php

@@ -19,7 +19,7 @@ public function __construct(Response $response){
         }
 
         if($response->getHeaders('Content-Type') == 'application/json'){
-            $message = $response->getJson()->error->message->value;
+            $message = $response->getJson()->error->message->value ?? $response->getJson()->error->message;
             $erroCode = $response->getJson()->error->code;
         }