Add support for multiple ad hosts for protokollsystem auth

protokollsystem/templates/config.py.j2

@@ -85,7 +85,15 @@ AUTH_MAX_DURATION = {{ protokolle_auth_max_duration }}
 AUTH_BACKENDS = [
 {% for auth in protokolle_auth_backends %}
     {{ auth.type }}(
+        {% if auth.host is defined %}
         host="{{ auth.host }}",
+        {% elif auth.hosts is defined %}
+        host=(
+        {% for host in auth.hosts %}
+        "{{host}}",
+        {% endfor %}
+        )
+        {% endif %}
         domain="{{ auth.domain }}",
         user_dn="{{ auth.user_dn }}",
         group_dn="{{ auth.group_dn }}",