Strip away copyrighted ICC profile

While checking for copyrighted ICC profiles, under non free licence
with a command like:

	find . -regextype posix-extended -iregex '.*\.(jpg|png)' \
		-exec sh -c 'identify -verbose "$0" \
		| grep -i copyright && echo "$0"' {} \;

The following file has been spotted, and the ICC profile has been
removed:

	exiftool -icc_profile"-<=" src/skin/menu-other-origins.png

The image has been checked identical to its source, and in addition,
the file is about 3 kB smaller without these useless binary data.