s->gss_sndtok in r8326. I'm not sure it was strictly necessary, since
even if there's no send token, gss_init_sec_context() is meant to explicitly
make it empty, but it wasn't an intentional change.
[originally from svn r8337]
[r8326 ==
81dafd906eb4817393fabe4d408c16de8586de8b]
/* initial tokens are empty */
SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
+ SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
/* now enter the loop */
do {