Fix bad sql connexion

models/User.php

@@ -179,7 +179,7 @@ class User {
             $stmt2->execute();
 
             // 2. On repasse TOUS leurs films en mode perso (is_common = 0)
-            $stmt = $this->db->prepare("UPDATE movies SET is_common = 0 WHERE user_id IN (?, ?)");
+            $stmt = $this->conn->prepare("UPDATE movies SET is_common = 0 WHERE user_id IN (?, ?)");
             $stmt->execute([$userId, $partnerId]);
 
             $this->conn->commit();