Fix the typo described in #320000

doc/ja/sources.list.ja.5.xml

@@ -391,7 +391,7 @@ deb http://http.us.debian.org/debian dists/stable-updates/
 <!--
    <para>Uses HTTP to access the archive at nonus.debian.org, under the
    debian-non-US directory, and uses only files found under
-   <filename>unstable/binary-i3866</filename> on i386 machines, 
+   <filename>unstable/binary-i386</filename> on i386 machines, 
    <filename>unstable/binary-m68k</filename> on m68k, and so
    forth for other supported architectures. [Note this example only 
    illustrates how to use the substitution variable; non-us is no longer