Add the possibility to pass extra flags to the docker container

roles/matrix-coturn/defaults/main.yml

@@ -23,6 +23,9 @@ matrix_coturn_systemd_required_services_list: ['docker.service']
 # Contains definition objects like this: `{"src": "/outside", "dst": "/inside", "options": "rw|ro|slave|.."}
 matrix_coturn_container_additional_volumes: []
 
+# A list of extra arguments to pass to the container
+matrix_coturn_container_extra_arguments: []
+
 # A shared secret (between Synapse and Coturn) used for authentication.
 # You can put any string here, but generating a strong one is preferred (e.g. `pwgen -s 64 1`).
 matrix_coturn_turn_static_auth_secret: ""