I personally would not inform him. Having anything in your car, including a firearm, has nothing to do with a traffic infraction. If, and it would be rare, you are asked to step out of the car then I would inform the officer. Furthermore, I find that very few officers ask if you have a CPL while driving. Even if asked if you have any weapons in the car, you are not obligated to respond. However, out of courtesy you might respond. And yes, as to officer safety, an officer may temporarily disarm someone.
Also, I suggest you do NOT admit to speeding or any other traffic violation.