allow request header overrides

MediaBrowser.Server.Implementations/HttpServer/RangeRequestWriter.cs

@@ -4,7 +4,6 @@ using System;
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
-using System.Linq;
 using System.Net;
 using System.Threading.Tasks;
 
@@ -84,7 +83,7 @@ namespace MediaBrowser.Server.Implementations.HttpServer
         /// </summary>
         private void SetRangeValues()
         {
-            var requestedRange = RequestedRanges.First();
+            var requestedRange = RequestedRanges[0];
 
             TotalContentLength = SourceStream.Length;