[Jenkins] Fix error with empty repolist

Fix NoneType fail when empty centos repolist provided.

Change-Id: I73b728b25238f43e0e6ba758077ce41336d72ba0

diff --git a/jenkins/build_cluster/build_cluster.py b/jenkins/build_cluster/build_cluster.py
index 283a96be45b3547f3ff46ea6a8aa3650610feb3f..8c4f1d70f2e3af6376c92c39dfd9addc74efa30d 100755 (executable)
--- a/jenkins/build_cluster/build_cluster.py
+++ b/jenkins/build_cluster/build_cluster.py
@@ -736,7 +736,7 @@ def main():
         subnet=cfg["ADMIN_SUBNET"],
         pswd = cfg["FUEL_SSH_PASSWORD"],)
 
-    if cfg["ADD_CENT_REPO"]!="":
+    if cfg["ADD_CENT_REPO"]!="" and cfg["ADD_CENT_REPO"] is not None:
         add_cent_repo(admin_node,cfg["ADD_CENT_REPO"])
 
     if cfg["UPDATE_FUEL"]=="true":