Your ROOT_URL in app.ini is https://src.whiteboxsystems.nl/ but you are visiting http://src.whiteboxsystems.nl/Whitebox/u-boot/src/commit/4fcd0b33c7a0db2e86cccdc1831db235a6bc1b2d/configs/O2MNT_defconfig
You should set ROOT_URL correctly, otherwise the web may not work correctly.