webui: prevent infinite reload for users with krbbprincipal alias set
    
    Web UI has inbuilt mechanism to reload in case response from a server
    contains a different principal than the one loaded during Web UI
    startup.
    
    see rpc.js:381
    
    With kerberos aliases support the loaded principal could be different
    because krbprincipalname contained multiple values.
    
    In such case krbcanonicalname should be used - it contains the same
    principal as the one which will be in future API responses.
    
    https://fedorahosted.org/freeipa/ticket/5927
    
    Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>