Your ROOT_URL in app.ini is https://src.whiteboxsystems.nl/ but you are visiting http://src.whiteboxsystems.nl/Whitebox/u-boot/src/commit/e7e75c70c5d5d3365606c4a76adb7ff4822d2f75/tools
You should set ROOT_URL correctly, otherwise the web may not work correctly.
At present mkimage is set up to always build with image signing support.
This means that the SSL libraries (e.g. libssl-dev) are always required.
Adjust things so that mkimage can be built with and without image signing,
controlled by the presence of CONFIG_FIT_SIGNATURE in the board config file.
If CONFIG_FIT_SIGNATURE is not enabled, then mkimage will report a warning
that signing is not supported. If the option is enabled, but libraries are
not available, then a build error similar to this will be shown:
lib/rsa/rsa-sign.c:26:25: fatal error: openssl/rsa.h: No such file or directory
Signed-off-by: Simon Glass <sjg@chromium.org>