Update ELK images

elasticsearch:
- https://github.com/docker-library/elasticsearch/commit/e773fb6: Update to 7.9.1

logstash:
- https://github.com/docker-library/logstash/commit/d3a4a18: Update to 7.9.1

kibana:
- https://github.com/docker-library/kibana/commit/57a6a97: Update to 7.9.1

library/elasticsearch

@@ -4,9 +4,9 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/elasticsearch.git
 
-Tags: 7.9.0
+Tags: 7.9.1
 Architectures: amd64, arm64v8
-GitCommit: 95f585fbba9baa25ac3acea6ae5fb938f09a7f67
+GitCommit: e773fb6d9c79d65310a0d6d41f9bf4f2cc336521
 Directory: 7
 
 Tags: 6.8.12

library/kibana

@@ -4,8 +4,8 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/kibana.git
 
-Tags: 7.9.0
-GitCommit: cee19912df82209e21583b7db91e0fc4e0a786db
+Tags: 7.9.1
+GitCommit: 57a6a9708ee050e740ffac635acfaf520c8f2f4b
 Directory: 7
 
 Tags: 6.8.12

library/logstash

@@ -4,8 +4,8 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/logstash.git
 
-Tags: 7.9.0
-GitCommit: 4991fcd34f4ac0925c57f785148c7368abaadc79
+Tags: 7.9.1
+GitCommit: d3a4a18b5337d706ea1ce614273cea71edf4d69d
 Directory: 7
 
 Tags: 6.8.12