Fix #4526 : Suppression des dates de fins de copyrights

ecrire/action/activer_plugins.php

ecrire/action/ajouter_lien.php

ecrire/action/annuler_job.php

ecrire/action/auth.php

ecrire/action/calculer_taille_cache.php

ecrire/action/confirmer_email.php

ecrire/action/confirmer_inscription.php

ecrire/action/converser.php

ecrire/action/cookie.php

ecrire/action/debloquer_edition.php

ecrire/action/desinstaller_plugin.php

ecrire/action/editer_article.php

ecrire/action/editer_auteur.php

ecrire/action/editer_liens.php

ecrire/action/editer_logo.php

ecrire/action/editer_objet.php

ecrire/action/editer_rubrique.php

ecrire/action/etre_webmestre.php

ecrire/action/forcer_job.php

ecrire/action/inscrire_auteur.php