Update mysql

Changes:

- https://github.com/docker-library/mysql/commit/6b30925: Merge pull request https://github.com/docker-library/mysql/pull/888 from infosiftr/mysql.conf.d
- https://github.com/docker-library/mysql/commit/19f5517: Add /etc/mysql/mysql.conf.d in 5.7 Oracle-based images

library/mysql

@@ -18,7 +18,7 @@ File: Dockerfile.debian
 
 Tags: 5.7.38, 5.7, 5, 5.7.38-oracle, 5.7-oracle, 5-oracle
 Architectures: amd64
-GitCommit: ea98f69d0bdab12f99731ed74e584317c246f3fd
+GitCommit: 19f5517b96ee5ee2aafb93dd7932a5e6bd3f0bc8
 Directory: 5.7
 File: Dockerfile.oracle