Update mySQL README for mySQL 8.0+ (#2126)
Update mySQL README for mySQL 8.0+ (#2126)

* Update mySQL README for mySQL 8.0+

* Update for comments

DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core