fix coturn url

templates/app/signaling-server/server.conf.j2

@@ -191,7 +191,7 @@ secret = {{ coturn_pass }}
 
 # A comma-separated list of TURN servers to use. Leave empty to disable the
 # TURN REST API.
-servers = turn:{{ ncloud_domain[0] }}:{{ coturn_port }}?transport=udp,turn:{{ ncloud_domain[0] }}:{{ coturn_port }}?transport=tcp
+servers = turn:{{ coturn_domain }}:{{ coturn_port }}?transport=udp,turn:{{ coturn_domain }}:{{ coturn_port }}?transport=tcp
 
 [geoip]
 # License key to use when downloading the MaxMind GeoIP database. You can