Raise the minimum required version of MySQL to 5.5.5

[desrosj]

In ​Core-57173, the minimum required version of MySQL was raised from 5.0 to 5.5.5. Let's make any necessary updates on the meta side of things.

My very short list so far is the ​Requirements page. But I'm sure there are more changes that need to occur.

[JavierCasares]

I did a quick check, and, although MySQL 5.5.x is insecure persé, the least insecure version is 5.5.30 (there is 5.5.62).

If not, at least, 5.5.24 because before that, there are possible DDOS.

The 5.5.30 is for an SSL think.

[paulkevan]

My very short list so far is the Requirements page.

It isn't widely used across the site - unlike PHP version, which we have shortcodes for.

Change minimum MYSQL version, as per ​https://core.trac.wordpress.org/changeset/57173

props desrosj.

See: https://meta.trac.wordpress.org/ticket/7363

[paulkevan]

Content updated to reflect ​https://core.trac.wordpress.org/changeset/57173.