Skip time sync during client install when using --no-ntp
    
    When --no-ntp is specified during ipa-client-install, we still
    attempt to perform a time sync before obtaining a TGT from the
    KDC.  We should not be attempting to sync time with the KDC if
    we are explicitly told to not configure ntp.
    
    Ticket: https://fedorahosted.org/freeipa/ticket/4842
    Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>