Allow people on books

MediaBrowser.Controller/Entities/Book.cs

@@ -24,6 +24,9 @@ namespace MediaBrowser.Controller.Entities
 
         public override bool SupportsPositionTicksResume => true;
 
+        [JsonIgnore]
+        public override bool SupportsPeople => true;
+
         [JsonIgnore]
         public string SeriesPresentationUniqueKey { get; set; }