Do not error out on empty rar file.

It avoids trying to play the file.
(cherry picked from commit 136942f307a3fee34c6a9f11353328f264e9027b)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/access/rar/stream.c

@@ -93,7 +93,7 @@ static int Open(vlc_object_t *object)
     int count;
     rar_file_t **files;
     const int64_t position = stream_Tell(s->p_source);
-    if (RarParse(s->p_source, &count, &files) || count <= 0) {
+    if (RarParse(s->p_source, &count, &files)) {
         stream_Seek(s->p_source, position);
         msg_Err(s, "Invalid or unsupported RAR archive");
         free(files);