ChangeDraftUpdate: Remove unused local variable

Change-Id: I3c878ac283e92ea89d8dd92c906e97bd57a08682
diff --git a/java/com/google/gerrit/server/notedb/ChangeDraftUpdate.java b/java/com/google/gerrit/server/notedb/ChangeDraftUpdate.java
index bb64766..d8390b7 100644
--- a/java/com/google/gerrit/server/notedb/ChangeDraftUpdate.java
+++ b/java/com/google/gerrit/server/notedb/ChangeDraftUpdate.java
@@ -174,7 +174,6 @@
 
     Map<RevId, RevisionNoteBuilder> builders = cache.getBuilders();
     boolean touchedAnyRevs = false;
-    boolean hasComments = false;
     for (Map.Entry<RevId, RevisionNoteBuilder> e : builders.entrySet()) {
       updatedRevs.add(e.getKey());
       ObjectId id = ObjectId.fromString(e.getKey().get());
@@ -185,7 +184,6 @@
       if (data.length == 0) {
         rnm.noteMap.remove(id);
       } else {
-        hasComments = true;
         ObjectId dataBlob = ins.insert(OBJ_BLOB, data);
         rnm.noteMap.set(id, dataBlob);
       }