VOL-1691 Fix openolt adapter getting stuck while registartion with core

Change-Id: Ide8131f325bc15f1b909e14d7af6ee9bcd6b3b5b
diff --git a/vendor/github.com/Shopify/sarama/fetch_request.go b/vendor/github.com/Shopify/sarama/fetch_request.go
index 462ab8a..4db9ddd 100644
--- a/vendor/github.com/Shopify/sarama/fetch_request.go
+++ b/vendor/github.com/Shopify/sarama/fetch_request.go
@@ -36,8 +36,8 @@
 type IsolationLevel int8
 
 const (
-	ReadUncommitted IsolationLevel = 0
-	ReadCommitted   IsolationLevel = 1
+	ReadUncommitted IsolationLevel = iota
+	ReadCommitted
 )
 
 func (r *FetchRequest) encode(pe packetEncoder) (err error) {