Get the language subdirectory for web admin

src/freedombone-utils-webadmin

@@ -415,11 +415,25 @@ function web_admin_create_installed_apps {
     chown -R www-data:www-data "/var/www/${local_hostname}/htdocs/admin"
 }
 
+function web_admin_get_language_subdir {
+    # Gets the subdirectory for the current language
+    # This is an upper case version of the first two characters of
+    # the config variable DEFAULT_LANGUAGE
+
+    read_config_param DEFAULT_LANGUAGE
+    if [ ! "$DEFAULT_LANGUAGE" ]; then
+        echo 'EN'
+        return
+    fi
+    lang_lower="${DEFAULT_LANGUAGE:0:2}"
+    echo "$lang_lower" | awk '{print toupper($0)}'
+}
+
 function install_web_admin {
     # This is intended as an admin web user interface
     # similar to Plinth or the yunohost
 
-    language_subdir='EN'
+    language_subdir=$(web_admin_get_language_subdir)
 
     local_hostname=$(grep 'host-name' /etc/avahi/avahi-daemon.conf | awk -F '=' '{print $2}').local