[BUG] Connected user doesn't show up in the system overview

[florianpunz]

OCS Inventory version
Version : OCS-NG_WINDOWS_AGENT_v2.10.1.0

Describe the bug
Everything shows up perfectly fine in Hardware, Software, Administrative data... etc. but in the "Active Computers" Overview, some PC's don't show the "Connected user". For some Computers it works fine, although they use the same version of OCS and were deployed the same way. About 50% of the machines don't show a connected user, but the computer is definetly in use and someone is logged in.

To Reproduce
Steps to reproduce the behavior:

1. I can't tell any difference between the machines its working and the ones where the user is empty, sorry.

Expected behavior
I expect it to just show up on every machine where someone is logged in and inventoried, because its working on some machines.

Screenshots

Log file (optional)
Apache / PHP / System log if needed