component AP gateway: AP delete activity => message retract: handle retractation of messages. As it is not possible to know from the AP item alone if we need to to a message retractation (XEP-0424) or a pubsub retractation (XEP-0060), we now cache sent message, and decide which method to use according to how the item is cached (i.e. in message history or in pubsub cache). rel 367

[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