Stop using deprecated worker settings (worker_replication_host, worker_replication_http_port)

Related to:
- e4f545c452
- 2481b7dfa4

We've prepared for this by adding the `main` process to the `instance_map` a long time ago,
in 49cb8b7b11.

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

@@ -5,11 +5,6 @@ worker_name: {{ matrix_synapse_worker_details.name }}
 worker_daemonize: false
 worker_log_config: /data/{{ matrix_server_fqn_matrix }}.log.config
 
-{% if matrix_synapse_replication_listener_enabled %}
-worker_replication_host: matrix-synapse
-worker_replication_http_port: {{ matrix_synapse_replication_http_port }}
-{% endif %}
-
 {% set http_resources = [] %}
 
 {% if matrix_synapse_worker_details.type == 'user_dir' %}