add code suggestions

Emby.Server.Implementations/Session/SessionManager.cs

@@ -1494,7 +1494,7 @@ namespace Emby.Server.Implementations.Session
             {
                 Limit = 1,
                 AccessToken = accessToken
-            }).Items[0];
+            }).Items.FirstOrDefault();
 
             if (existing != null)
             {

MediaBrowser.Controller/Session/SessionInfo.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Linq;
+using System.Text.Json.Serialization;
 using System.Threading;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Model.Dto;
@@ -124,6 +125,7 @@ namespace MediaBrowser.Controller.Session
         /// Gets or sets the session controller.
         /// </summary>
         /// <value>The session controller.</value>
+        [JsonIgnore]
         public ISessionController[] SessionControllers { get; set; }
 
         /// <summary>