fix: removed the read-only tag from the element-call systemd file.

roles/custom/matrix-element-call/templates/systemd/matrix-element-call.service.j2

@@ -19,7 +19,6 @@ ExecStartPre={{ devture_systemd_docker_base_host_command_docker }} create \
     --log-driver=none \
     --user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
     --cap-drop=ALL \
-    --read-only \
     --network={{ matrix_element_call_container_network }} \
     {% if matrix_element_call_container_http_host_bind_port %}
     -p {{ matrix_element_call_container_http_host_bind_port }}:8080 \