Cardigann: fix form login

src/Jackett/Indexers/CardigannIndexer.cs

@@ -477,6 +477,8 @@ namespace Jackett.Indexers
                 }
 
                 // selector inputs
+                if (Login.Selectorinputs != null)
+                {
                     foreach (var Selectorinput in Login.Selectorinputs)
                     {
                         string value = null;
@@ -490,6 +492,7 @@ namespace Jackett.Indexers
                             throw new Exception(string.Format("Error while parsing selector input={0}, selector={1}, value={2}: {3}", Selectorinput.Key, Selectorinput.Value.Selector, value, ex.Message));
                         }
                     }
+                }
 
                 // automatically solve simpleCaptchas, if used
                 var simpleCaptchaPresent = landingResultDocument.QuerySelector("script[src*=\"simpleCaptcha\"]");