Enable nullabe reference types for MediaBrowser.Model

MediaBrowser.Model/Services/QueryParamCollection.cs

@@ -1,3 +1,4 @@
+#nullable disable
 #pragma warning disable CS1591
 
 using System;
@@ -19,11 +20,6 @@ namespace MediaBrowser.Model.Services
             return StringComparison.OrdinalIgnoreCase;
         }
 
-        private static StringComparer GetStringComparer()
-        {
-            return StringComparer.OrdinalIgnoreCase;
-        }
-
         /// <summary>
         /// Adds a new query parameter.
         /// </summary>