add case for auth token retrieval timing out

Author: roninopf

ios/RNIterableAPI/ReactIterableAPI.swift

@@ -571,6 +571,9 @@ extension ReactIterableAPI: IterableAuthDelegate {
                 DispatchQueue.main.async {
                     completion(self.passedAuthToken)
                 }
+            } else {
+                ITBInfo("authTokenRetrieval timed out")
+                completion(nil)
             }
         }
     }