Fix parse errors with link-local addresses
    
    Link-local addresses received from netifaces contains '%suffix' that
    causes parse error in IPNetwork class. We must remove %suffix before
    it us used in IPNetwork objects.
    
    https://fedorahosted.org/freeipa/ticket/6296
    
    Reviewed-By: Tomas Krizek <tkrizek@redhat.com>