The Python 2 and 3 versions of chardet both install a script with the
same name (/usr/bin/chardetect). This is the issue identified in #9006
(https://github.com/openwrt/packages/pull/9006#issuecomment-493709812).

This renames the Python 3 script to chardetect3.

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

Signed-off-by: Eneas U de Queiroz <cote2004-github@yahoo.com>

Signed-off-by: Karel Kočí <karel.koci@nic.cz>