add shared secret config

rootfs/etc/confd/templates/server.yaml.tmpl

@@ -8,7 +8,7 @@ server_name: "{{getenv "SERVER_NAME"}}"
 pid_file: /var/lib/synapse/homeserver.pid
 
 web_client: True
-public_baseurl: https://{{getenv "SERVER_NAME"}}:8448/
+public_baseurl: https://{{getenv "SERVER_NAME"}}/
 
 soft_file_limit: 0
 
@@ -91,6 +91,8 @@ thumbnail_sizes:
 url_preview_enabled: False
 enable_registration_captcha: False
 
+registration_shared_secret: "{{getenv "SHARED_SECRET"}}"
+
 # The public URIs of the TURN server to give to clients
 turn_uris: []