title: iOS: FBSDKShareDialog custom message
body: <p>I'm creating the FBSDKShareLinkContent object and feeding it into the FBSDKShareDialog. I'm trying to set up the dialog's default message to something like "my highscore is %d !". sharing itself is working and has an empty message by default. can anyone help please?</p>
  
  <p>thank you!</p>
  
  <p>EDIT: here is my piece of code:</p>
  
  <pre><code>FBSDKShareLinkContent* content = [[FBSDKShareLinkContent alloc] init];
  content.contentURL = [NSURL URLWithString: @"https://itunes.apple.com/us/app/cylinder-game"];
  content.contentTitle = @"Cylinder Game";
  content.contentDescription = @"Cylinder Game is endless, rhythm based game with super addictive gameplay";
  
  FBSDKShareDialog* dialog = [[FBSDKShareDialog alloc] init];
  [dialog setMode:FBSDKShareDialogModeAutomatic];
  [dialog setShareContent:content];
  [dialog setDelegate:self];
  [dialog setFromViewController:UnityGetGLViewController()];
  </code></pre>