Rubicon: Remove unnecessary property

[Compile-Ninja]

🔧 Type of changes

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

✨ What's the context?

What's the context for the changes? Are there any

🧠 Rationale behind the change

Why did you choose to make these changes? Were there any trade-offs you had to consider?

🧪 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?