1496fb7 ipa-adtrust-install: Allow dash in the NETBIOS name

Authored and Committed by tbabej 8 years ago
    ipa-adtrust-install: Allow dash in the NETBIOS name
    
    Dash should be one of the allowed characters in the netbios names,
    so relax the too strict validation.
    
    Note: the set of allowed characters might expand in the future
    
    https://fedorahosted.org/freeipa/ticket/5286
    
    Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>