I am not sure whether what I have done is "correct", but one may follow the following steps if you get stuck the same way.
The "issue" takes place in the "download_pkg" function. You may find it in the tool_kit.sh in the scripts folder.
It was not necessary probably, but I pasted it in the get_openblas_arch.sh script file.
I've added the "--no-check-certificate" in the line:
local __wget_flags='--quiet --no-check-certificate'
It did download fine afterwards.