Clean legacy permissions when upgrading

scripts/upgrade

@@ -16,6 +16,12 @@ ynh_clean_setup () {
 }
 ynh_abort_if_errors
 
+ynh_script_progression --message="Ensuring downward compatibility..."
+if ynh_legacy_permissions_exists; then
+	ynh_legacy_permissions_delete_all
+	ynh_app_setting_delete --app=$app --key=is_public
+fi
+
 ynh_script_progression --message="Making sure dedicated system user exists..."
 ynh_system_user_create --username=$app --home_dir="$final_path"