XXX comment in the logic which sends failed password auth back to username

prompt for keyboard-interactive. I suspect we should do the same with that
method (especially given the apparent number of systems that use it for
regular password auth), but in the absence of systems to test against I've
not actually made the change. (I'm worried that the `partial success' field
might not be set correctly in a multi-stage authentication, for instance.)

[originally from svn r4850]

ssh.c

@@ -5020,6 +5020,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 			logevent("Access denied");
 			if (s->type == AUTH_TYPE_PASSWORD &&
 			    ssh->cfg.change_username) {
+			    /* XXX perhaps we should allow
+			     * keyboard-interactive to do this too? */
 			    s->we_are_in = FALSE;
 			    break;
 			}