HttpContentHeadersExtensions.AddHeaders: Bugfix: Remove undesired header validation (#25)

HttpContentHeadersExtensions.AddHeaders is used by DecompressedContent to copy response content headers to the DecompressedContent headers. Content header validation is not needed and not performed on uncompressed content.

Author: onyxmaster

StandardSocketsHttpHandler/Net/Http/Extensions/HttpContentHeadersExtensions.cs

@@ -10,7 +10,7 @@ public static void AddHeaders(this HttpContentHeaders headers, HttpContentHeader
         {
             foreach (KeyValuePair<string, IEnumerable<string>> header in sourceHeaders)
             {
-                headers.Add(header.Key, header.Value);
+                headers.TryAddWithoutValidation(header.Key, header.Value);
             }
         }
     }