Change default Certificate Handling Mode of integrated web server in taglist

The default Certificate Handling Mode of the integrated web server will be changed towards WEBSERVER_SECURITY_SELF_CFG_MODE_ON_ERROR to ensure that, in the event of a faulty or inconsistent certificate, the web server generates a new private key and a self-signed certificate automatically.

This change is necessary because a mission-critical Firmware Update mechanism is implemented through the web server. To ensure the availability of the update process, it is crucial to prioritize availability over integrity in the default case. This will ensure the web server remains operational, even if the certificate is compromised or invalid, enabling uninterrupted firmware updates.