matrix: Improve our coturn config a bit

Be explicit about the ports used and enable packet fingerprinting
(checksumming). Both for better compatibility.

roles/matrix/templates/homeserver.yaml.j2

@@ -1125,10 +1125,10 @@ url_preview_accept_language:
 # The public URIs of the TURN server to give to clients
 #
 turn_uris:
-  - "turns:{{ matrix_domain }}?transport=udp"
-  - "turns:{{ matrix_domain }}?transport=tcp"
-  - "turn:{{ matrix_domain }}?transport=udp"
-  - "turn:{{ matrix_domain }}?transport=tcp"
+  - "turns:{{ matrix_domain }}:5349?transport=udp"
+  - "turns:{{ matrix_domain }}:5349?transport=tcp"
+  - "turn:{{ matrix_domain }}:3478?transport=udp"
+  - "turn:{{ matrix_domain }}:3478?transport=tcp"
 
 # The shared secret used to compute passwords for the TURN server
 #

roles/matrix/templates/turnserver.conf.j2

@@ -2,6 +2,9 @@
 min-port=33000
 max-port=33999
 
+# Uncomment to use fingerprints in the TURN messages.
+fingerprint
+
 # TURN REST API flag.
 use-auth-secret