Allow configuring PERMITTED_METADATA_DOMAINS in proto3

uwsgi-python/templates/apps/protokollsystem.j2

@@ -39,6 +39,9 @@ URL_PARAMS = ""
 {% if cdn_url is defined %}
 CDN_URL = "{{cdn_url}}"
 {% endif %}
+{% if protokolle_metadata_domain_whitelist is defined %}
+PERMITTED_METADATA_DOMAINS = [ {% for domain in protokolle_metadata_domain_whitelist %} "{{domain}}", {% endfor %} ]
+{% endif %}
 
 PRINTING_ACTIVE = {{ protokolle_printing }}
 PRINTING_SERVER = "{{ protokolle_printing_server }}"