Comment 2 for bug 1673742

With the removal of bpickle module (replaced with bpickle3 module), Landscape server code can't use it from the landscape-client/common deb packages as it used to:

  https://ci.lscape.net/job/landscape-package/3578/console
  https://lunchtimeprediction.com/teatime-predictions

Let's fix that by renaming bpickle3 back to bpickle since it is backwards compatible.