Merge branch 'fix-elasticsearch-indexer-worker-ce-14427' into 'master'

Exit ElasticIndexerWorker's job happily if record cannot be found

Fixes gitlab-org/gitlab-ce#14427.

See merge request !311

CHANGELOG-EE

@@ -3,6 +3,9 @@ Please view this file on the master branch, on stable branches it's out of date.
 v 8.7.0 (unreleased)
   - Update GitLab Pages to 0.2.1: support user-defined 404 pages
 
+v 8.6.3 (unreleased)
+  - Exit ElasticIndexerWorker's job happily if record cannot be found. !311
+
 v 8.6.2
   - Fix old commits triggering git hooks on new branches branched off another branch. !281
   - Fix issue with deleted user in audit event (Stan Hu). !284

app/workers/elastic_indexer_worker.rb

 class ElasticIndexerWorker
   include Sidekiq::Worker
-  
+
   sidekiq_options queue: :elasticsearch
 
   Client = Elasticsearch::Client.new(host: Gitlab.config.elasticsearch.host,
@@ -19,6 +19,8 @@ class ElasticIndexerWorker
 
       clear_project_indexes(record_id) if klass == Project
     end
+  rescue Elasticsearch::Transport::Transport::Errors::NotFound
+    true # Less work to do!
   end
 
   def clear_project_indexes(record_id)