[frankie_douhan]

To be honest. You don't have a kodi problem, but one with your base system installation.

If you were on Ubuntu (yes, you are not):

sudo apt-get install ca-certificates

and done. I wish you luck.

Any reason for this selfmade pain? Making something secure and then copying local crt / pem files around makes zero sense.  

Thanks a lot for your help. It made me change curl installation and now it works. 
Any reason for this selfmade pain? - I just like the things made by myself is the first reason. There are a lots more but I don't want to argue about them. Thank a lot one more time