Production builds still try to live reload

[oliverzheng]

Describe the bug
In the developer console, I can see socket.io network requests being sent for a production build. E.g. on https://book-book-mailing.vercel.app/

To Reproduce
Steps to reproduce the behavior:

1. Go to https://book-book-mailing.vercel.app/previews/Reservation/reservationWithError
2. Open dev console
3. See network requests for pulling.

Weirdly, only some of the demos on the Mailing website experience this.

Expected behavior
No live reload happens on production build.

Screenshots

Desktop (please complete the following information):

• OS: Mac OS X 13.1
• Browser: Chrome
• Version: 109.0.5414.119

Additional context

[psugihara]

Good catch. Let's remove that by checking if NODE_ENV === "production"

[marcincodes]

@psugihara This issue can be closed. Fix was merged here: #483