How does one globally disable device notifications

Hi,

We've recently moved from 4:14.0.4 on Debian jessie to 4:14.0.6 on Debian stretch and all of our users (remote displays via tdm/XDMCP) are getting device popups when a usb device is connected (daily change of SSD for backup for example).

How do I globally disable this?

I've tried putting a kdedrc in my global profile directory containing:

[Module-mediamanager][$i] autoload=false

[Module-medianotifier][$i] autoload=false

but that doesn't seem to do it.

Any ideas?