[VOL-5249] error loading onos image in voltha-onos-sanity_test

Change-Id: I8011343d7c53d033e3b568b5b04ff6531a56344b
diff --git a/vars/getVolthaImageFlags.groovy b/vars/getVolthaImageFlags.groovy
index 7543615..a4127f9 100644
--- a/vars/getVolthaImageFlags.groovy
+++ b/vars/getVolthaImageFlags.groovy
@@ -48,7 +48,7 @@
             break
         case 'voltha-onos':
             String ans = [
-                '--set nos-classic.image.repository=voltha/voltha-onos',
+                '--set onos-classic.image.repository=voltha/voltha-onos',
                 'onos-classic.image.tag=citest',
                 "onos-classic.image.pullPolicy=${pullPolicy}",
             ].join(',')