http: check certificate validity before clobbering the error variable
static void http_stream_free(git_smart_subtransport_stream *stream)
{
	http_stream *s = (http_stream *)stream;

	if (s->chunk_buffer)
		git__free(s->chunk_buffer);

	if (s->redirect_url)
		git__free(s->redirect_url);

	git__free(s);
}

static void http_stream_free(git_smart_subtransport_stream *stream)
{
	http_stream *s = (http_stream *)stream;

	if (s->chunk_buffer)
		git__free(s->chunk_buffer);

	if (s->redirect_url)
		git__free(s->redirect_url);

	git__free(s);
}
