"p" letter at the bottom of comment form

Hello.

I have a “p” letter à the bottom of my comment form.

If I change the theme, it is still here.

Can be seen here : https://www.parigotmanchot.fr/2016/06/19/evolution-parc-informatique-personnel-2-modifications-materielles-installations/

Seems there is a problem, as I tested lots of plugins :/

I disabled last 2 : WP Super Cache + a recaptcha plugin.

Any idea ?

Thanks.