probably a pretty simple question but how do I change the log format for FPM logs? An Entry looks like this for im in stderr:

2017/12/12 10:59:09 [error] 17#17: *6 FastCGI sent in stderr: "PHP message: 2017-12-12 11:59:09 > WARNING > WarningId: 1234 [] 

The thing I want to remove is the [error] part because in this example I'm logging a warning via monolog.