[ISSUE-71761531] add comments

listener.go

diff --git a/listener.go b/listener.go
index 2c4862a..97fdb9d 100644
--- a/listener.go
+++ b/listener.go
@@ -46,6 +46,7 @@
 	}
 	// add indexes
 	if err := common.AddIndexes(snapshot.SnapshotInfo); err != nil {
+		// not on critical path, continue in case of error
 		log.Errorf("Failed to add KMS indexes: %v", err)
 	}
 	// retrieve encryption keys