0fa6c4d kra install: update installation failure message

Authored and Committed by tkrizek 6 years ago
    kra install: update installation failure message
    
    When installation fails, do not advise the user to use the
    obsoleted --uninstall option.
    
    Signed-off-by: Tomas Krizek <tkrizek@redhat.com>
    Fixes https://pagure.io/freeipa/issue/6923
    
    Reviewed-By: Martin Basti <mbasti@redhat.com>