[10.x] Display error message if json_encode() fails (#48856)

* Display error message if json_encode() fails

Adding the error code to the exception isn't useful. Instead, the error message can give details about the problem.

* Added error code as suggested

* Fixed coding style issue

Author: aimeos

src/Illuminate/Queue/Queue.php

@@ -107,7 +107,7 @@ protected function createPayload($job, $queue, $data = '')
 
         if (json_last_error() !== JSON_ERROR_NONE) {
             throw new InvalidPayloadException(
-                'Unable to JSON encode payload. Error code: '.json_last_error(), $value
+                'Unable to JSON encode payload. Error ('.json_last_error().'): '.json_last_error_msg(), $value
             );
         }