`input` in blue ocean UI can not react against multi user id definition

[Hanks Justin]

Hi, I use pipeline like below:

```

timeout(time: 5, unit: "DAYS") {

    input message: "Do you want to approve this job to deploy to production?", ok: "OK", submitter: "userA,userB,userC"

}

```

and in the old UI, it works fine, all the users can presss the `OK` button, but in the blue ocean UI, no one can press `OK` button.

Is this a bug or something, thank you for your time.