[Administration] Emails automatiques > ajout : correctif erreur quand "Jour d'envoi" est vide

domain/Communication/AutomaticEmail/AutomaticEmail.php

         return $this;
     }
 
-    public function getSendingDay(): ?int
+    public function getSendingDay()
     {
         return $this->sending_day;
     }

domain/Communication/AutomaticEmail/AutomaticEmailManager.php

         int $day = null,
         PointSale $pointSale = null,
         int $delayBeforeDistribution = null,
-        int $sendingDay = null,
+        $sendingDay = null,
         int $sendingHour = null,
         bool $integrateProductList = null
     ): AutomaticEmail