Fixed: (Cardigann) Don't try re-auth if can't html parse json

src/NzbDrone.Core/Indexers/Definitions/Cardigann/CardigannRequestGenerator.cs

@@ -924,6 +924,9 @@ namespace NzbDrone.Core.Indexers.Cardigann
                 return true;
             }
 
+            // Only run html test selector on html responses
+            if (response.Headers.ContentType.Contains("text/html"))
+            {
                 var parser = new HtmlParser();
                 var document = parser.ParseDocument(response.Content);
 
@@ -935,6 +938,7 @@ namespace NzbDrone.Core.Indexers.Cardigann
                         return true;
                     }
                 }
+            }
 
             return false;
         }