[Fixed] McAfee Stinger TTF and regsistry left behind

1. There's a leftover left by McAfee Stinger at "C:\Program Files\stinger". Inside it there's a font file "OpenSans-Regular-webfont.ttf". The app deserves a fix so it is removed automatically at shutdown.
2. Another thing is an empty registry key at "HKEY_LOCAL_MACHINE\SOFTWARE\McAfee".