use global variables

webserver/docker_icinga/templates/etc/icinga/conf.d/users_groups.conf

@@ -9,8 +9,8 @@ object User "matrix" {
   display_name = "Matrix User"
   vars.matrix = {
     token = "{{ matrix_notification_access_token }}"
-    channel = "!iYefxbySFEfFQfUGEK:matrix.warpzone.ms"
-    server = "https://matrix.warpzone.ms"
+    channel = "{{ matrix.notifications_room_id }}"
+    server = "{{ matrix.public_url }}"
   }
 }