Hi,
if you have a look inside it:
identify -verbose logo.png
you'll see it contains
Profiles:
Profile-icc: 3144 bytes
Description: sRGB IEC61966-2.1
Manufacturer: IEC http://www.iec.ch
Model: IEC 61966-2.1 Default RGB colour space - sRGB
Copyright: Copyright (c) 1998 Hewlett-Packard Company
The copyrighted ICC profile has no license, hence you can't know if you're allowed to redistribute that file or not.
You can either edit the file, or just remove it.