"Ranked Match" (QM) doesn't launch on linux

Pressing Ranked Match, which used to open the quickmatch program, no longer works in the new client. If you connect the process to a terminal, you can see the following output:

```
xdg-open: file 'Qt\CnCNetQM.exe' does not exist 
```

Tested on Client Version 8.67.3

The binary launches fine with wine as before, so the path just needs to be fixed so it works across platforms.