Add test case for pki config override
    
    Install CA with 4096bit RSA key and SHA-384 signature.
    
    Fixes: https://pagure.io/freeipa/issue/5608
    Signed-off-by: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Fraser Tweedale <ftweedal@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>