Fixing grammatical errors in error message

[RaneWallin]

Fixing a small grammatical error in the error message, neither/nor clause and that/which confusion.

[facebook-github-bot]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. In order for us to review and merge your code, please sign up at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need the corporate CLA signed.

If you have received this in error or have any questions, please contact us at cla@fb.com. Thanks!

[sizebot]

No significant bundle size changes to report.

Generated by 🚫 dangerJS against 24b8518

[facebook-github-bot]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Facebook open source project. Thanks!

[pconley]

you probably already figured this out, but you also need to change the test at
https://github.com/facebook/react/blob/master/packages/eslint-plugin-react-hooks/__tests__/ESLintRulesOfHooks-test.js#L761

[threepointone]

lgtm, thank you!