rename artifactory cleanup job to artifact cleanup

Change-Id: Ic504e1e6f28f11c1aeb83ba4727b5aa66fa70ee6
diff --git a/jjb/metal3/projects.yml b/jjb/metal3/projects.yml
index 7701da4..2d707b3 100644
--- a/jjb/metal3/projects.yml
+++ b/jjb/metal3/projects.yml
@@ -43,7 +43,7 @@
         image_os:
           - ubuntu
           - centos
-    - artifactory_cleanup
+    - artifact_cleanup
     repo:
       org: "Nordix"
       name: "metal3-dev-tools"