(Minor) auth.ts uses deprecated http.ServerRequest

[PopGoesTheWza]

Fixes #477

• npm run test succeeds.
• npm run lint succeeds.
• Appropriate changes to README are included in PR.

'npm run test` had errors but they do not seem related to the changes in PR
No need to update README.md

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[PopGoesTheWza]

I have a CLA now...

[googlebot]

CLAs look good, thanks!

[takanakahiko]

#478 (comment)

In markdown you can check by entering x between [and] .

- [ ] no checked
- [x] checked

[PopGoesTheWza]

@takanakahiko I fixed it. Thanks.

[grant]

Thanks!