Adapt external_prometheus.yml.example.j2 to our new metrics exposure setup

roles/custom/matrix-synapse/templates/synapse/prometheus/external_prometheus.yml.example.j2

@@ -12,28 +12,28 @@ rule_files:
 scrape_configs:
   - job_name: 'synapse'
     metrics_path: /metrics/synapse/main-process
-    scheme: {{ 'https' if matrix_nginx_proxy_https_enabled|default(true) else 'http' }}
-{% if matrix_nginx_proxy_proxy_matrix_metrics_basic_auth_enabled|default(true) %}
+    scheme: https
+{% if matrix_synapse_container_labels_metrics_middleware_basic_auth_enabled|default(true) %}
     basic_auth:
       username: prometheus
       password_file: /path/to/your/passwordfile.pwd
 {% endif %}
     static_configs:
-      - targets: ['{{ matrix_server_fqn_matrix }}:{{ matrix_nginx_proxy_container_https_host_bind_port|default(443) if matrix_nginx_proxy_https_enabled|default(true) else matrix_nginx_proxy_container_http_host_bind_port|default(80) }}']
+      - targets: ['{{ matrix_synapse_metrics_proxying_hostname }}:443']
         labels:
           job: "master"
           index: "0"
 {% for worker in matrix_synapse_workers_enabled_list %}
   - job_name: '{{ worker.name }}'
     metrics_path: /metrics/synapse/worker/{{ worker.id }}
-    scheme: {{ 'https' if matrix_nginx_proxy_https_enabled|default(true) else 'http' }}
-{% if matrix_nginx_proxy_proxy_matrix_metrics_basic_auth_enabled|default(true) %}
+    scheme: https
+{% if matrix_synapse_worker_container_labels_metrics_middleware_basic_auth_enabled|default(true) %}
     basic_auth:
       username: prometheus
       password_file: /path/to/your/passwordfile.pwd
 {% endif %}
     static_configs:
-      - targets: ['{{ matrix_server_fqn_matrix }}:{{ matrix_nginx_proxy_container_https_host_bind_port|default(443) if matrix_nginx_proxy_https_enabled|default(true) else matrix_nginx_proxy_container_http_host_bind_port|default(80) }}']
+      - targets: ['{{ matrix_synapse_metrics_proxying_hostname }}:443']
         labels:
           worker_id: {{ worker.id }}
           job: "{{ worker.type }}"