Possible fix for MrMC

MediaBrowser.Api/Playback/Progressive/BaseProgressiveStreamingService.cs

@@ -280,18 +280,24 @@ namespace MediaBrowser.Api.Playback.Progressive
         /// <param name="isHeadRequest">if set to <c>true</c> [is head request].</param>
         /// <param name="cancellationTokenSource">The cancellation token source.</param>
         /// <returns>Task{System.Object}.</returns>
-        private async Task<object> GetStaticRemoteStreamResult(StreamState state, Dictionary<string, string> responseHeaders, bool isHeadRequest, CancellationTokenSource cancellationTokenSource)
+        private async Task<object> GetStaticRemoteStreamResult(
+            StreamState state,
+            Dictionary<string, string> responseHeaders,
+            bool isHeadRequest,
+            CancellationTokenSource cancellationTokenSource)
         {
-            state.RemoteHttpHeaders.TryGetValue(HeaderNames.UserAgent, out var useragent);
-
             var options = new HttpRequestOptions
             {
                 Url = state.MediaPath,
-                UserAgent = useragent,
                 BufferContent = false,
                 CancellationToken = cancellationTokenSource.Token
             };
 
+            if (state.RemoteHttpHeaders.TryGetValue(HeaderNames.UserAgent, out var useragent))
+            {
+                options.UserAgent = useragent;
+            }
+
             var response = await HttpClient.GetResponse(options).ConfigureAwait(false);
 
             responseHeaders[HeaderNames.AcceptRanges] = "none";
@@ -306,7 +312,7 @@ namespace MediaBrowser.Api.Playback.Progressive
             {
                 using (response)
                 {
-                    return ResultFactory.GetResult(null, new byte[] { }, response.ContentType, responseHeaders);
+                    return ResultFactory.GetResult(null, Array.Empty<byte>(), response.ContentType, responseHeaders);
                 }
             }