HttpProvider.PostCommand will no longer keep the connection alive

src/NzbDrone.Common/Http/NzbDroneWebClient.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Net;
+
+namespace NzbDrone.Common.Http
+{
+    public class NzbDroneWebClient : WebClient
+    {
+        protected override WebRequest GetWebRequest(Uri address)
+        {
+            var request = base.GetWebRequest(address);
+            if (request is HttpWebRequest)
+            {
+                ((HttpWebRequest)request).KeepAlive = false;
+            }
+
+            return request;
+        }
+    }
+}