When an authentication error occurs SPICE_CLIENT_ERROR_AUTH_NEEDS_PASSWORD or
SPICE_CLIENT_ERROR_AUTH_NEEDS_PASSWORD_AND_USERNAME is returned as a channel
error. But it can happen that only username is needed when you use e.g. GSSAPI.
It would be useful to have SPICE_CLIENT_ERROR_AUTH_NEEDS_USERN
When an authentication error occurs SPICE_CLIENT_ERROR_AUTH_NEEDS_PASSWORD or
SPICE_CLIENT_ERROR_AUTH_NEEDS_PASSWORD_AND_USERNAME is returned as a channel
error. But it can happen that only username is needed when you use e.g. GSSAPI.
It would be useful to have SPICE_CLIENT_ERROR_AUTH_NEEDS_USERN
