Resolve "Tell people to rebase themselves when ee-specific-lines-check failed to rebase"

What does this MR do?

Tell people to rebase themselves when ee-specific-lines-check failed to rebase

Are there points in the code the reviewer needs to double check?

My English :P

Does this MR meet the acceptance criteria?

• Conforms to the code review guidelines
  • Has been reviewed by a Backend maintainer

What are the relevant issue numbers?

Closes #6915 (closed)