Just do it again. If you have something like
Re: what ever the subject is
Maybe put:
Re: what ever the subject is – Correction
In law there is a term called Nunc pro tunc.
It means “now for then” which is a latin way of saying, I am doing something now that I should have done then. So in situations where there is a time limit/deadline it’s sometimes useful to be doing something now which ideally should have been done previously. such as misquoting a law or missing something previously and now correcting that.