Fix uninitialized variable in get_refs_via_rsync().

This fixes a crash when cloning via rsync://.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

transport.c

@@ -143,7 +143,7 @@ static const char *rsync_url(const char *url)
 static struct ref *get_refs_via_rsync(struct transport *transport, int for_push)
 {
 	struct strbuf buf = STRBUF_INIT, temp_dir = STRBUF_INIT;
-	struct ref dummy, *tail = &dummy;
+	struct ref dummy = {0}, *tail = &dummy;
 	struct child_process rsync;
 	const char *args[5];
 	int temp_dir_len;