Fix Traefik load balancer port for matrix-mx-puppet-slack

roles/custom/matrix-bridge-mx-puppet-slack/templates/labels.j2

@@ -5,7 +5,7 @@ traefik.enable=true
 traefik.docker.network={{ matrix_mx_puppet_slack_container_labels_traefik_docker_network }}
 {% endif %}
 
-traefik.http.services.matrix-mx-puppet-slack.loadbalancer.server.port={{ matrix_mx_puppet_slack_appservice_address }}
+traefik.http.services.matrix-mx-puppet-slack.loadbalancer.server.port={{ matrix_mx_puppet_slack_appservice_port }}
 
 {% if matrix_mx_puppet_slack_container_labels_public_endpoint_enabled %}
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