Oneliner: erase incorrect memcached keys on demand

We had a situation where our image thumbnail memcached cluster somehow got empty thumbnails. The thumbnails are generated on the fly by image proxy servers and the thumbnail is stored into memcached. For some reason some of the thumbnails were truncated. As I didn’t have time to start debugging the real issue, I quickly wrote this oneliner which detects corrupted thumbnails when the thumbnail is fetched from the memcached and issues a delete operation to it.