chown artifacts to jenkins so we can delete them

Change-Id: I49400ca6c828e6855a755e5eb81246e6b684976a
diff --git a/jobs.yaml b/jobs.yaml
index 479e50c..55b1ed3 100644
--- a/jobs.yaml
+++ b/jobs.yaml
@@ -58,6 +58,7 @@
     builders:
       - shell: stdbuf -oL -eL mispipe "~mininet/mininet/util/vm/build.py -v --branch {branch} --test sanity {flavor}"  "tr '\r' ' '"
       - shell: zip `basename -s .ovf */*.ovf`.zip */*.vmdk */*.ovf
+      - shell: sudo chown -R jenkins  `dirname */build.log`
     publishers:
       - archive:
             artifacts: '**'