Update undulator.py to remove incorrect PV's

Goetz removed some PV's so these devices stopped being able to connect.

https://mattermost.hzdr.de/hzb-acc-support/pl/txbagg9d4bdk9xsr81m6gw3h8y

I corrected the missing PV's.

NOTE these PV's only update at 1HZ. We should identify how to use the faster updating PV's. This also doesn't address the done signal failing for small moves https://openproject.helmholtz-berlin.de/projects/epics/work_packages/2116/activity