Your ROOT_URL in app.ini is https://src.whiteboxsystems.nl/ but you are visiting http://src.whiteboxsystems.nl/Whitebox/u-boot/blame/commit/896a74f615d6ffcbbcbec1505b19ed3280fe7873/configs/mx6ull_14x14_evk_defconfig
You should set ROOT_URL correctly, otherwise the web may not work correctly.