Fix wifi auto connect

config.example

-# Configuration wifi
-WPA_ESSID=mon_ssid
-WPA_PASSWORD=mon_mdp
+# Automatically connect to a wifi network on first boot
+WPA_ESSID=my_ssid
+WPA_PASSWORD=my_password
+WPA_COUNTRY=FR
 
-# Nom de la machine
+# Machine name
 IMG_NAME=thymio-raspbian
 TARGET_HOSTNAME=thymio-raspbian
 
-# Configuration de la langue
+# Language
 LOCALE_DEFAULT=fr_FR.UTF-8
 KEYBOARD_KEYMAP=fr
 KEYBOARD_LAYOUT=fr
 TIMEZONE_DEFAULT=Europe/Paris
 
-# Nom et mot de passe de l'utilisateur
+# User name and password
 FIRST_USER_NAME=pi
 FIRST_USER_PASS=rasberry
 
-# Activer un serveur SSH
+# Enable ssh server for remote log in
 ENABLE_SSH=1