Update the "No Engineer" example for FW 2026.0

The "No Engineer" example describes how the name of the OPC UA server configuration file must be PCWE.opcua.config. This will be changed in the upcoming firmware version 2026.0 - the reference to PLCnext Engineer ("PCWE") in the file name will be removed.
The example should be updated when FW 2026.0 is released.