Error whilst creating TANs from the backend

[marcuslelle]

Bug description

Creating a number of TANs for one survey through the backend leads to an error message instead:

[2023-07-31T15:24:16.592722+02:00] request.CRITICAL: Uncaught PHP Exception TypeError: "ceil(): Argument #1 ($num) must be of type int|float, string given" at /html/contao413/vendor/pdir/contao-survey/src/Resources/contao/classes/SurveyPINTAN.php line 229 {"exception":"[object] (TypeError(code: 0): ceil(): Argument #1 ($num) must be of type int|float, string given at /html/contao413/vendor/pdir/contao-survey/src/Resources/contao/classes/SurveyPINTAN.php:229)"} []

Steps to reproduce

Choose a survey.
Click on "TAN-Codes erzeugen".
Type in a number of TANs to create, e.g. 5.

Expected behavior

Creating a number of TANs (e.g. 5 as I requested in the form).

Environment

PHP 8.2.5
Contao 4.13.28
contao-survey 3.5.0