Your ROOT_URL in app.ini is https://src.whiteboxsystems.nl/ but you are visiting http://src.whiteboxsystems.nl/Whitebox/u-boot/blame/commit/f5fd45ff64e28a73499548358e3d1ceda0de7daf/configs/theadorable_defconfig
You should set ROOT_URL correctly, otherwise the web may not work correctly.