ublox module missing

As part of the Copter-4.1 beta testing a user found that the ublox module was not available and I've confirmed as well. I'm unsure if it's a code issue or a documentation issue.

The failure message is, "Failed to load module: No module named 'ublox'. Use 'set moddebug 3' in the MAVProxy console to enable traceback"

wiki: https://ardupilot.org/mavproxy/docs/modules/ublox.html
discussion: https://discuss.ardupilot.org/t/ublox-assistnow-with-gps-via-ap-periph/70631/4

Start with the linked ublox module wiki page and the discussion thread, then reproduce the reported MAVProxy error and inspect how the module is made available. Determine whether the missing module is a code or documentation problem; done means the module is available as documented or the documentation accurately reflects its status.

Written by the indexing model from the issue text.