Update mysql

Changes:

- https://github.com/docker-library/mysql/commit/3dfa7a3: Update to 8.0.19-1debian9
- https://github.com/docker-library/mysql/commit/6952c5d: Update to 5.7.29-1debian9
- https://github.com/docker-library/mysql/commit/4ee6cf3: Update to 5.6.47-1debian9

library/mysql

@@ -4,14 +4,14 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/mysql.git
 
-Tags: 8.0.18, 8.0, 8, latest
-GitCommit: 6659750146b7a6b91a96c786729b4d482cf49fe6
+Tags: 8.0.19, 8.0, 8, latest
+GitCommit: 3dfa7a3c038f342b9dec09fa85247bef69ae2349
 Directory: 8.0
 
-Tags: 5.7.28, 5.7, 5
-GitCommit: 6659750146b7a6b91a96c786729b4d482cf49fe6
+Tags: 5.7.29, 5.7, 5
+GitCommit: 6952c5d5a9889311157362c528d65dc2e37ff660
 Directory: 5.7
 
-Tags: 5.6.46, 5.6
-GitCommit: 6659750146b7a6b91a96c786729b4d482cf49fe6
+Tags: 5.6.47, 5.6
+GitCommit: 4ee6cf34697d33b2f71144ef55f96867b71220d5
 Directory: 5.6