Out of your whole essay…no no … Your WHOLE application. Do you think that one sentence is gonna be the reason you don’t get in (if you don’t correct it) or the reason you actually get in (if you correct it? Do you think the admissions officer/committee is gonna say ‘oh no. We have to reject this kid because of this sentence.’?
I doubt it. So I guess there’s no need for an update. 
And like others already said, they won’t even notice.