Shared posts do not show image

if the fb post is a shared one the image extracted is not valid.

includes/class-api.php 43:
$result = $this->call(“{$this->fb_id}/posts”, array(
‘fields’ => ‘id,full_picture,picture,type,from,message,status_type,object_id,name,caption,description,link,created_time,comments.limit(1).summary(true),likes.limit(1).summary(true)’
));
// NEW full_picture

includes/class-api.php 114:
case ‘photo’:
// set post image, use protocol relative URL
$post[‘image’] = “//graph.facebook.com/”. $p->object_id . ‘/picture’;
// NEW we use full_picture because the default one in this case is a small one (130x130px)
if($p->status_type == ‘shared_story’){
$post[‘image’] = $p->full_picture;
}
//NEW
break;