fix 'A is not defined error' in the big pinwheel

This is a trivial diff, so I will not be offended in the least if you do not merge it or even reply.

I love this animation, so I tried fixing a glitch to explore how it works.

I removed the endElement() after 10 seconds, as nothing happens on Chrome
or Firefox except a console reference error 'A is not defined'.

I am not sure what is supposed to happen after 10 seconds (stop? turn yellow again and restart?), so I didn't propose any code to replace the lines I removed.

I did not test my changes with Internet Explorer or Safari. As far as I can tell from quick demos on Sauce Labs, the pin wheel does not move on those browsers.

The small pinwheel has the same glitch, but I didn't include it in the pull request.