Merge branch 'stable-2.13'

* stable-2.13:
  Drain executor of index change requests before closing index

Change-Id: I2d676adf60d2eab0f9f7602b124574050af0ee3d

gerrit-acceptance-framework/src/test/java/com/google/gerrit/acceptance/ReadOnlyChangeIndex.java

@@ -46,6 +46,10 @@ public class ReadOnlyChangeIndex implements ChangeIndex {
     index.close();
   }
 
+  @Override
+  public void stop() {
+  }
+
   @Override
   public void replace(ChangeData obj) throws IOException {
     // do nothing