Using custom ONOS image for further logging in ATT job

Change-Id: I9cd154fb64315a92deef3500145cdfd706a9b685
diff --git a/jjb/voltha-scale.yaml b/jjb/voltha-scale.yaml
index 96166b8..0b56630 100644
--- a/jjb/voltha-scale.yaml
+++ b/jjb/voltha-scale.yaml
@@ -63,6 +63,7 @@
           withDhcp: true
           withIgmp: false
           extraHelmFlags: '--set authRetry=true,dhcpRetry=true --set global.log_correlation.enabled=true -f /home/jenkins/voltha-scale/voltha-values.yaml'
+          onosImg: andreacampanella/voltha-onos:olt-group-pkt-req-mcast-fix
           bbsimImg: matteoscandolo/bbsim:gemport
 
       - 'voltha-scale-measurements':