✨(backend) notify collaboration server

When an access is updated or removed, the
collaboration server is notified to reset the
access connection; by being disconnected, the
accesses will automatically reconnect by passing
by the ngnix subrequest, and so get the good
rights.
We do the same system when the document link is
updated, except here we reset every access
connection.

src/helm/env.d/dev/values.impress.yaml.gotmpl

@@ -6,6 +6,7 @@ image:
 backend:
   replicas: 1
   envVars:
+    COLLABORATION_API_URL: https://impress.127.0.0.1.nip.io/collaboration/api/
     COLLABORATION_SERVER_SECRET: my-secret
     DJANGO_CSRF_TRUSTED_ORIGINS: https://impress.127.0.0.1.nip.io,http://impress.127.0.0.1.nip.io
     DJANGO_CONFIGURATION: Feature