Zipping the combined error-report.log file to disk overflow

Change-Id: Ia1e644b7343e28f566248ebfe7e768ed7b12a573
diff --git a/jjb/pipeline/voltha-go-multi-tests.groovy b/jjb/pipeline/voltha-go-multi-tests.groovy
index 762ea02..2c49f4c 100644
--- a/jjb/pipeline/voltha-go-multi-tests.groovy
+++ b/jjb/pipeline/voltha-go-multi-tests.groovy
@@ -147,6 +147,8 @@
          extract_errors_go voltha-ofagent >> $WORKSPACE/error-report.log
          extract_errors_python onos >> $WORKSPACE/error-report.log
 
+         gzip error-report.log || true
+
          cd $HOME/kind-voltha/scripts/logger/combined/
          tar czf $WORKSPACE/container-logs.tgz *