Can not update backends

[cedk]

I can not update the application because it fails when updating the backend:

---[Updating backend tryton-rietveld-hrd]---
../google_appengine/appcfg.py  backends update . --application `cat app.yaml | sed -n 's/^application: *//p'` --version `git log --pretty=format:'%h' -n 1`"-tainted"
08:31 PM Application: tryton-rietveld-hrd
08:31 PM Warning: This application uses Backends, a deprecated feature that has been replaced by Modules, which offers additional functionality. Please convert your backends to modules as described at: https://developers.google.com/appengine/docs/python/modules/converting
08:31 PM Host: appengine.google.com
08:31 PM Starting update of app: tryton-rietveld-hrd, backend: mapreduce-backend
08:31 PM Getting current resource limits.
08:31 PM Scanning files on local disk.
Could not guess mimetype for static/autocomplete/README.  Using application/octet-stream.
Error 400: --- begin server output ---
The version field in the app.yaml file must match the version provided as a GET parameter.
--- end server output ---
make: *** [Makefile:73: update_backend] Error 1

I think it is because backends API has been shutdown: https://cloud.google.com/appengine/docs/deprecations/backends-api