fix: pass list for turn_uris

.env.sample

@@ -18,6 +18,6 @@ SYNAPSE_ADMIN_EMAIL=admin@example.com
 
 #COMPOSE_FILE="compose.yml:compose.turn.yml"
 #TURN_ENABLED=1
-#TURN_URI=
+#TURN_URIS=["turn:turn.example.com?transport=udp", "turn:turn.example.com?transport=tcp"]
 #TURN_ALLOW_GUESTS=true
 #SECRET_TURN_SHARED_SECRET_VERSION=v1

homeserver.yaml.tmpl

@@ -1127,7 +1127,7 @@ oembed:
 
 # The public URIs of the TURN server to give to clients
 #
-turn_uris: ["{{ env "TURN_URI" }}"]
+turn_uris: {{ env "TURN_URIS" }}
 
 # The shared secret used to compute passwords for the TURN server
 #