Don't send empty auth data
diff --git a/_modules/jenkins_common.py b/_modules/jenkins_common.py
index c7446fa..348aa09 100644
--- a/_modules/jenkins_common.py
+++ b/_modules/jenkins_common.py
@@ -69,7 +69,7 @@
 
     logger.debug("Calling Jenkins script API with URL: %s", jenkins_url)
     req = requests.post('%s/scriptText' % jenkins_url,
-                        auth=(jenkins_user, jenkins_password),
+                        auth=(jenkins_user, jenkins_password) if jenkins_user else None,
                         data=req_data)
     ret["code"] = req.status_code
     ret["msg"] = req.text