Fixed: (Torrent RSS) Clear old cookies on edit

Fixes #2275

src/NzbDrone.Core/Indexers/Definitions/TorrentRss/TorrentRssIndexer.cs

@@ -1,4 +1,6 @@
 using System.Collections.Generic;
+using System.Threading.Tasks;
+using FluentValidation.Results;
 using NLog;
 using NzbDrone.Core.Configuration;
 using NzbDrone.Core.Messaging.Events;
@@ -44,6 +46,13 @@ namespace NzbDrone.Core.Indexers.Definitions.TorrentRss
             }
         }
 
+        protected override Task<ValidationFailure> TestConnection()
+        {
+            UpdateCookies(null, null);
+
+            return base.TestConnection();
+        }
+
         private IndexerDefinition GetDefinition(string name, string description, TorrentRssIndexerSettings settings)
         {
             return new IndexerDefinition

src/NzbDrone.Core/Indexers/HttpIndexerBase.cs

@@ -650,7 +650,7 @@ namespace NzbDrone.Core.Indexers
             {
                 foreach (var cookie in Cookies)
                 {
-                    request.HttpRequest.Cookies.Add(cookie.Key, cookie.Value);
+                    request.HttpRequest.Cookies[cookie.Key] = cookie.Value;
                 }
             }