[pjsip] REINVITE authentication

[mayamatakeshi]

Hello,
I am testing making calls with pjsip to an authenticating proxy and
everything goes fine as I'm calling pjsip_auth_clt_set_credentials.
But if I need to send a REINVITE, when I call
pjsip_inv_reinvite/pjsip_inv_send_msg, pjsip is  not sending
authentication headers when the proxy replies with '407 Proxy
Authentication Required'.
I even tried to call pjsip_auth_clt_set_credentials again, before
calling pjsip_inv_send_msg but it doesn't work.
Is there anything else I should do?

regards,
takeshi