plugin XEP-0167: handle conferences: - SDP can now be answered by component instead of frontend. This is useful for A/V conferences component to handle A/V call jingle sessions. - new `call_update` and method, and `content-add` action preparation. This is not yet used by A/V conference, but it's a preparation for a potential future use. - Add NS_AV_CONFERENCES to features as required by the newly proposed A/V Conferences protoXEP. rel 447

[DEFAULT]
xmpp_domain = server1.test
email_server = libervia-backend.test
email_port = 8025
email_admins_list = admin@server1.test

[component file-sharing]
tls_certificate = /usr/share/libervia/certificates/server1.test.pem
tls_private_key = /usr/share/libervia/certificates/server1.test-key.pem
http_upload_public_facing_url = https://libervia-backend.test:8888