demux_libarchive: escape '%' in stream URL path

Opening paths that are detected as archives which contain
'%[0-9A-Fa-f][0-9A-Fa-f]' will fail, because such sequence is treated as
a percent-encoded value when the path gets unescaped causing the path to
be mangled. Escape '%' to prevent this from happening.

Fixes: 2b280f4522 ("stream: libarchive wrapper for reading compressed archives")

demux/demux_libarchive.c

@@ -76,7 +76,7 @@ static int open_file(struct demuxer *demuxer, enum demux_check check)
     struct playlist *pl = talloc_zero(demuxer, struct playlist);
     demuxer->playlist = pl;
 
-    char *prefix = mp_normalize_path(NULL, mp_url_escape(mpa, demuxer->stream->url, "~|"));
+    char *prefix = mp_normalize_path(NULL, mp_url_escape(mpa, demuxer->stream->url, "~|%"));
 
     char **files = NULL;
     int num_files = 0;