Merge branch 'stable-2.13'

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

Change-Id: I2d676adf60d2eab0f9f7602b124574050af0ee3d

gerrit-server/src/test/java/com/google/gerrit/server/index/change/FakeChangeIndex.java

@@ -108,4 +108,8 @@ public class FakeChangeIndex implements ChangeIndex {
   public void markReady(boolean ready) {
     throw new UnsupportedOperationException();
   }
+
+  @Override
+  public void stop() {
+  }
 }