NextMillennium : Revert "NextMillennium: Adapter and server version (#3773)"

[Net-burst]

This reverts commit c5e6906.

🔧 Type of changes

• new bid adapter
• bid adapter update
• new feature
• new analytics adapter
• new module
• module update
• bugfix
• documentation
• configuration
• dependency update
• tech debt (test coverage, refactorings, etc.)

✨ What's the context?

This PR broke the NetMillennium endpoint.

🔎 New Bid Adapter Checklist

• verify email contact works
• NO fully dynamic hostnames
• geographic host parameters are NOT required
• direct use of HTTP is prohibited - implement an existing Bidder interface that will do all the job
• if the ORTB is just forwarded to the endpoint, use the generic adapter - define the new adapter as the alias of the generic adapter
• cover an adapter configuration with an integration test

🧪 Test plan

How do you know the changes are safe to ship to production?

🏎 Quality check

• Are your changes following our code style guidelines?
• Are there any breaking changes in your code?
• Does your test coverage exceed 90%?
• Are there any erroneous console logs, debuggers or leftover code in your changes?

[Net-burst]

There is an issue in the initial porting PR: #3773
The new object should be in the request.ext whereas it was added to the request.imp[].ext. This chokes the endpoint.
@przemkaczmarek please create a new pull request with a fix. I've reopened the porting issue #3744