SUP and OBS are shown as controllers

[svengcz]

Describe the bug Clients that are logged in as SUP or OBS are listed as controllers, but they aren't controllers.

To Reproduce Steps to reproduce the behavior:

1. Start VATprism
2. Open Controllers tab

Expected behavior A list of all active ATC controllers without SUPs and OBSs.

[marvk]

This is working as intended, though arguably, some observers are logged in the pilot client with a pilot-like callsign. I'll have to have a look at the data so see if I can discern pilot observers from controller observers.