Fix Safari crashing when entering into description editor
Source https://framacolibri.org/t/lors-de-la-creation-d-un-evenement-le-navigateur-se-bloque/6081, confirmed with another person.
Source https://framacolibri.org/t/lors-de-la-creation-d-un-evenement-le-navigateur-se-bloque/6081, confirmed with another person.