My son's pediatrician has a mild-moderate stutter. When he's having a bad speech day, he'll stutter a bit. At which point, I remember - oh, he has a stutter -- because otherwise I completely forget because who cares? And then life goes on. He's also AOA from a top medical school and residency program and has been a wonderful physician for my son and my family. The guy's great -- who cares about a little speech thing?
Bottom line -- Having a stutter does not make you either less intelligent or less capable. Furthermore, it does not make you seem either less intelligent or less capable. It's just a little something unique to you, that's really not even all that unique.
Do you need to disclose it? No - Because if it happens, it'll be self-evident. And when it doesn't happen, it doesn't matter.