webui: allow --force in dnszone-mod and dnsrecord-add
    
    Allow to use --force when changing authoritative nameserver address in DNS zone.
    
    Same for dnsrecord-add for NS record.
    
    https://fedorahosted.org/freeipa/ticket/4573
    
    Reviewed-By: Endi Sukma Dewata <edewata@redhat.com>