Session cookie setting being set while session is active

Trying to do will raise a warning since PHP 7.2, and it never worked as intented.
See: https://bugs.php.net/bug.php\?id\=75650

index.php

@@ -243,7 +243,9 @@ function isLoggedIn()
         }
 
         // Send cookie with the new expiration date to the browser
+        session_destroy();
         session_set_cookie_params($expirationTime, $cookiedir, $_SERVER['SERVER_NAME']);
+        session_start();
         session_regenerate_id(true);
 
         // Optional redirect after login: