Next Middleware bug using Netlify CLI

Steps to reproduce

1. Clone this repo (created using npx create-next-app)
2. Run npm run dev
3. You should see "middleware" in the console and xxx-header added to the response
4. Stop the server
5. Run netlify dev
6. "middleware" is not logged to the console and xxx-header is not added to the response
7. Stop the Netlify dev server
8. Run npm run dev again
9. Still no "middleware" in the console and xxx-header is not added to the response
10. Run rm -rf node_modules
11. Run npm install
12. Run npm run dev
13. Should see "middleware" in the console again and xxx-header added to the response