fix: add missing ISSUER_2FA default

imageroot/update-module.d/11set_twofa_provider

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+
+#
+# Copyright (C) 2024 Nethesis S.r.l.
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+
+# sets a 2FA provider in the config.env file
+with open('config.env', 'a+') as file:
+    already_exists = False
+    fqdn = ''
+    while line := file.readline():
+        if line.startswith('FQDN'):
+            fqdn = line.split('=')[1].strip()
+        if line.startswith('ISSUER_2FA'):
+            already_exists = True
+    if not already_exists:
+        file.write(f'ISSUER_2FA={fqdn}\n')