fix win32 zooming - return default dpi value if detection fails
fix win32 zooming - return default dpi value if detection fails

bobi32/gummi,turbopobre/gummi,alexandervdm/gummi,mlda065/gummi,bobi32/gummi,turbopobre/gummi,turbopobre/gummi,bobi32/gummi,mlda065/gummi,alexandervdm/gummi,bobi32/gummi,turbopobre/gummi,alexandervdm/gummi,mlda065/gummi,mlda065/gummi