Fix helpers test: SimpleHTTPServer was python2 only, use http.server for python3/bullseye
Fix helpers test: SimpleHTTPServer was python2 only, use http.server for python3/bullseye

YunoHost/yunohost,YunoHost/moulinette-yunohost,YunoHost/moulinette-yunohost,YunoHost/yunohost,YunoHost/moulinette-yunohost,YunoHost/moulinette-yunohost,YunoHost/yunohost,YunoHost/moulinette-yunohost,YunoHost/yunohost