Application hangs at startup for some Windows clients

[sbancal]

Apparently the wmic bin on some rare Windows desktop could not be found in PATH
This is used in :

• ENACdrives/client/win_stack.py

  Line 38 in 27f69ba

  NonBlockingQtProcess.invalidate_cmd_cache(["wmic", "logicaldisk"])

• ENACdrives/client/win_stack.py

  Line 73 in 27f69ba

  cmd = ["wmic", "logicaldisk"] # List all Logical Disks

This cause the application to not complete its initialization ... And the user can't do anything to mount or open a drive.