Add validation check for matrix_nginx_proxy_container_labels_traefik_proxy_matrix_federation_hostname

roles/custom/matrix_playbook_migration/tasks/validate_config.yml

@@ -301,6 +301,7 @@
         - {'old': 'matrix_nginx_proxy_proxy_synapse_additional_server_configuration_blocks', 'new': '<removed>'}
         - {'old': 'matrix_nginx_proxy_proxy_matrix_additional_server_configuration_blocks', 'new': '<removed>'}
         - {'old': 'matrix_nginx_proxy_access_log_enabled', 'new': 'devture_traefik_config_accessLog_enabled'}
+        - {'old': 'matrix_nginx_proxy_container_labels_traefik_proxy_matrix_federation_hostname', 'new': '<matrix_synapse_container_labels_public_federation_api_traefik_hostname for Synapse; matrix_dendrite_container_labels_public_federation_api_traefik_hostname for Dendrite; matrix_conduit_container_labels_public_federation_api_traefik_hostname for Conduit'}
         - {'old': 'etherpad_nginx_proxy_dimension_integration_enabled', 'new': '<removed>'}
         - {'old': 'etherpad_nginx_proxy_dimension_integration_path_prefix', 'new': '<removed>'}
         - {'old': 'matrix_prometheus_services_proxy_connect_prometheus_node_exporter_metrics_proxying_enabled', 'new': '<removed>'}