PENSACOLA, Fla. — Amtrak’s passenger rail service between Mobile and New Orleans is expected to begin early next year. But it may be bad news for Northwest Florida. On Tuesday, the Mobile City Council had a unanimous vote in favor of the project. But an amendment added to the leasing agreement states the contact with Amtrak would be void if it tries to extend service north or east of Mobile.That could block Pensacola’s efforts to bring passenger rail service here.