Fixed: uTorrent api proxy would fail on specific Win10 configurations. (The Phoenix Rises)

Moved token queryparam to start since uTorrent requires it.
Fixed handling response missing an expected Set-Cookie header.
Force Cache-Control: no-cache for uTorrent.
Added Connection: KeepAlive to fix inexplicable uTorrent api failure.

src/NzbDrone.Common/Http/Dispatchers/ManagedHttpDispatcher.cs

@@ -17,7 +17,7 @@ namespace NzbDrone.Common.Http.Dispatchers
 
             webRequest.Method = request.Method.ToString();
             webRequest.UserAgent = UserAgentBuilder.UserAgent;
-            webRequest.KeepAlive = false;
+            webRequest.KeepAlive = request.ConnectionKeepAlive;
             webRequest.AllowAutoRedirect = request.AllowAutoRedirect;
             webRequest.CookieContainer = cookies;
 

src/NzbDrone.Common/Http/HttpRequest.cs

@@ -35,6 +35,7 @@ namespace NzbDrone.Common.Http
         public string ContentSummary { get; set; }
         public bool SuppressHttpError { get; set; }
         public bool AllowAutoRedirect { get; set; }
+        public bool ConnectionKeepAlive { get; set; }
         public Dictionary<string, string> Cookies { get; private set; }
         public bool StoreResponseCookie { get; set; }
         public TimeSpan RequestTimeout { get; set; }

src/NzbDrone.Common/Http/HttpRequestBuilder.cs

@@ -20,6 +20,7 @@ namespace NzbDrone.Common.Http
         public HttpHeader Headers { get; private set; }
         public bool SuppressHttpError { get; set; }
         public bool AllowAutoRedirect { get; set; }
+        public bool ConnectionKeepAlive { get; set; }
         public NetworkCredential NetworkCredential { get; set; }
         public Dictionary<string, string> Cookies { get; private set; }
         public List<HttpFormData> FormData { get; private set; }
@@ -98,6 +99,7 @@ namespace NzbDrone.Common.Http
             request.Method = Method;
             request.SuppressHttpError = SuppressHttpError;
             request.AllowAutoRedirect = AllowAutoRedirect;
+            request.ConnectionKeepAlive = ConnectionKeepAlive;
 
             if (NetworkCredential != null)
             {
@@ -232,6 +234,13 @@ namespace NzbDrone.Common.Http
             return this;
         }
 
+        public virtual HttpRequestBuilder KeepAlive(bool keepAlive = true)
+        {
+            ConnectionKeepAlive = keepAlive;
+
+            return this;
+        }
+
         public virtual HttpRequestBuilder Post()
         {
             Method = HttpMethod.POST;
@@ -253,6 +262,19 @@ namespace NzbDrone.Common.Http
             return this;
         }
 
+        public virtual HttpRequestBuilder AddPrefixQueryParam(string key, object value, bool replace = false)
+        {
+            if (replace)
+            {
+                QueryParams.RemoveAll(v => v.Key == key);
+                SuffixQueryParams.RemoveAll(v => v.Key == key);
+            }
+
+            QueryParams.Insert(0, new KeyValuePair<string, string>(key, value.ToString()));
+
+            return this;
+        }
+
         public virtual HttpRequestBuilder AddQueryParam(string key, object value, bool replace = false)
         {
             if (replace)

src/NzbDrone.Common/Http/HttpResponse.cs

@@ -61,7 +61,10 @@ namespace NzbDrone.Common.Http
         {
             var result = new Dictionary<string, string>();
 
-            foreach (var cookie in Headers.GetValues("Set-Cookie"))
+            var setCookieHeaders = Headers.GetValues("Set-Cookie");
+            if (setCookieHeaders != null)
+            {
+                foreach (var cookie in setCookieHeaders)
                 {
                     var match = RegexSetCookie.Match(cookie);
                     if (match.Success)
@@ -69,6 +72,7 @@ namespace NzbDrone.Common.Http
                         result[match.Groups[1].Value] = match.Groups[2].Value;
                     }
                 }
+            }
 
             return result;
         }

src/NzbDrone.Core/Download/Clients/uTorrent/UTorrentProxy.cs

@@ -158,6 +158,8 @@ namespace NzbDrone.Core.Download.Clients.UTorrent
         {
             var requestBuilder = new HttpRequestBuilder(false, settings.Host, settings.Port)
                 .Resource("/gui/")
+                .KeepAlive()
+                .SetHeader("Cache-Control", "no-cache")
                 .Accept(HttpAccept.Json);
 
             requestBuilder.NetworkCredential = new NetworkCredential(settings.Username, settings.Password);
@@ -248,7 +250,7 @@ namespace NzbDrone.Core.Download.Clients.UTorrent
             }
 
             requestBuilder.SetCookies(cookies);
-            requestBuilder.AddQueryParam("token", authToken, true);
+            requestBuilder.AddPrefixQueryParam("token", authToken, true);
         }
     }
 }