Add missing comma back into /about/stats names list.
Add missing comma back into /about/stats names list.

This was causing stats.json to look for an 'escrowngivers' key in globals(), completely breaking it

mccolgst/www.gittip.com,gratipay/gratipay.com,eXcomm/gratipay.com,eXcomm/gratipay.com,studio666/gratipay.com,studio666/gratipay.com,eXcomm/gratipay.com,mccolgst/www.gittip.com,mccolgst/www.gittip.com,bountysource/www.gittip.com,bountysource/www.gittip.com,mccolgst/www.gittip.com,studio666/gratipay.com,gratipay/gratipay.com,eXcomm/gratipay.com,bountysource/www.gittip.com,gratipay/gratipay.com,studio666/gratipay.com,bountysource/www.gittip.com,gratipay/gratipay.com