Jetpack: Enhanced Open Graph: dropping Gravatar fallback, to mirror what is done with Twitter Cards, because there is no way for us to know if we're getting a user's gravatar or a falback one when an author has none.


git-svn-id: https://plugins.svn.wordpress.org/jetpack/trunk@809028 b8457f37-d9ea-0310-8a92-e5e31aec5664