mender show-artifact gives SSL errors

After running through onboarding I ran the following command:

pi@raspberrypi:~ $ sudo mender -show-artifact
ERRO[0000] Failed to Load the Server certificate. Err SSL errors:  
WARN[0000] Failed to load the server TLS certificate settings: SSL errors:  
hello-world
pi@raspberrypi:~ $ 

Why does it show these SSL errors? They seem to be empty as well?
This is also the case if you run "show-provides" and potentially other local commands.

After some initial investigation:

It seems to be triggered by incorrect use of "ClientProtocol" field in mender.conf, which to our current knowledge we shouldn't need and should be completely removed.

Acceptance criteria:

• ClientProtocol is removed from mender.conf
• mTLS via OpenSSL works as expected