Added Nzbget version check for 12.0 or higher.

src/NzbDrone.Core/Download/Clients/Nzbget/Nzbget.cs

@@ -254,7 +254,12 @@ namespace NzbDrone.Core.Download.Clients.Nzbget
         {
             try
             {
-                _proxy.GetVersion(Settings);
+                var version = _proxy.GetVersion(Settings);
+
+                if (Version.Parse(version) < Version.Parse("12.0"))
+                {
+                    return new ValidationFailure(string.Empty, "Nzbget version too low, need 12.0 or higher");
+                }
             }
             catch (Exception ex)
             {

src/NzbDrone.Core/Download/Clients/Nzbget/NzbgetProxy.cs

@@ -86,7 +86,7 @@ namespace NzbDrone.Core.Download.Clients.Nzbget
         {
             var request = BuildRequest(new JsonRequest("version"));
 
-            return Json.Deserialize<NzbgetResponse<String>>(ProcessRequest(request, settings)).Version;
+            return Json.Deserialize<NzbgetResponse<String>>(ProcessRequest(request, settings)).Result;
         }
 
         public Dictionary<String, String> GetConfig(NzbgetSettings settings)