Remove undefined extra_tgt variable

Change-Id: I44b4bb420fc0bb40c136aa4417c367acd18f54a4
PROD-related: PROD-31257
diff --git a/stacklight-upgrade.groovy b/stacklight-upgrade.groovy
index b81ef97..4627fad 100644
--- a/stacklight-upgrade.groovy
+++ b/stacklight-upgrade.groovy
@@ -70,7 +70,7 @@
             common.errorMsg('[ERROR] Elasticsearch VIP port could not be retrieved')
         }
 
-        pillar = salt.getReturnValues(salt.getPillar(master, "I@elasticsearch:client ${extra_tgt}", 'elasticsearch:client:server:scheme'))
+        pillar = salt.getReturnValues(salt.getPillar(master, "I@elasticsearch:client", 'elasticsearch:client:server:scheme'))
         def elasticsearch_scheme
         if(pillar) {
             elasticsearch_scheme = pillar