Fix an exception in the kafka client. Update gitignore to ignore
only proto files generated by Voltha.

Change-Id: I54b1b5e428a918ab20e564b55176942d0bc0facd
diff --git a/kafka/kafka_inter_container_library.go b/kafka/kafka_inter_container_library.go
index 72abe9e..c0670d3 100644
--- a/kafka/kafka_inter_container_library.go
+++ b/kafka/kafka_inter_container_library.go
@@ -741,10 +741,7 @@
 
 func (kp *InterContainerProxy) unSubscribeForResponse(trnsId string) error {
 	log.Debugw("unsubscribe-for-response", log.Fields{"trnsId": trnsId})
-	if _, exist := kp.transactionIdToChannelMap[trnsId]; exist {
-		// The delete operation will close the channel
-		kp.deleteFromTransactionIdToChannelMap(trnsId)
-	}
+	kp.deleteFromTransactionIdToChannelMap(trnsId)
 	return nil
 }