Also trigger on https://login.digid.nl (which is also used by some services)

Moved away from window.onload as it was not reliably triggering the script

Fix:
- In the normal DigiD flow, the user goes through a few steps before the QR code is shown. The script has already run then, so the DigiD logo is not removed. This update will continually scan for the logo and remove it when it is rendered