Fix some comments in worker-labels for Synapse

Related to 929aee3022 and
https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3154

roles/custom/matrix-synapse/templates/synapse/worker-labels.j2

@@ -8,7 +8,7 @@ traefik.docker.network={{ matrix_synapse_worker_container_labels_traefik_docker_
 traefik.http.services.{{ matrix_synapse_worker_container_name }}-metrics.loadbalancer.server.port={{ matrix_synapse_worker_details.metrics_port }}
 
 {#
-	Metrics (e.g. /metrics/synapse/__WORKER_ID__)
+	Metrics (e.g. /metrics/synapse/worker/__WORKER_ID__)
 #}
 {% if matrix_synapse_worker_container_labels_public_metrics_enabled %}
 
@@ -42,7 +42,7 @@ traefik.http.routers.{{ matrix_synapse_worker_container_name }}-metrics.tls.cert
 
 {% endif %}
 {#
-	/Metrics (e.g. /metrics/synapse/__WORKER_ID__)
+	/Metrics (e.g. /metrics/synapse/worker/__WORKER_ID__)
 #}