Upgrade gravatar2 package to fix escaping issue.
Upgrade gravatar2 package to fix escaping issue.

rtfd/readthedocs.org,tddv/readthedocs.org,pombredanne/readthedocs.org,davidfischer/readthedocs.org,rtfd/readthedocs.org,safwanrahman/readthedocs.org,safwanrahman/readthedocs.org,rtfd/readthedocs.org,rtfd/readthedocs.org,davidfischer/readthedocs.org,pombredanne/readthedocs.org,davidfischer/readthedocs.org,davidfischer/readthedocs.org,safwanrahman/readthedocs.org,pombredanne/readthedocs.org,tddv/readthedocs.org,tddv/readthedocs.org,safwanrahman/readthedocs.org