message: add self_video support
diff: @@ -550,6 +550,8 @@ export interface Voice_State {
  self_mute: boolean;
  /** whether this user is streaming using "Go Live" */
  self_stream?: boolean;
  + /** whether this user's camera is enabled */
  + self_video?: boolean;
  /** whether this user is muted by the current user */
  suppress: boolean;
  }
  