Windows: Fix, adding to the PATH variable was using a broken check to detect Windows.
Windows: Fix, adding to the PATH variable was using a broken check to detect Windows.

tempbottle/Nuitka,kayhayen/Nuitka,wfxiang08/Nuitka,tempbottle/Nuitka,kayhayen/Nuitka,wfxiang08/Nuitka,tempbottle/Nuitka,wfxiang08/Nuitka,tempbottle/Nuitka,kayhayen/Nuitka,wfxiang08/Nuitka,kayhayen/Nuitka