Needs porting to FreeRDP 3.x

I had assumed based on 4ff283a7 that KRdp builds with FreeRDP 3, but that is apparently not the case currently.

Fedora is switching to FreeRDP 3 for Fedora 40, but it currently fails to build with my commit to bump to FreeRDP 3.

Here's a full build log from the Fedora Rawhide package build: 80f8d261.txt