MFH: r542203

databases/mysq56-{client, server}: Update to latest release 5.6.49

Full changelog: https://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-49.html

Security: 0ed71663-c369-11ea-b53c-d4c9ef517024
Sponsored by: Netzkommune GmbH

Approved by: ports-secteam (wit hat)