Update Jira MySQL documentation in regards to installing Jira and Confluence on the same database server

In our Connecting Jira applications to MySQL 5.7 documentation, there is a bullet at the top with the following information:

If you plan to set up Confluence and Jira on the same MySQL server, read the Confluence MySQL setup guide. Confluence requirements are more strict than Jira's, so you should configure MySQL to suit Confluence. This configuration will work for Jira, too.

Since the release of Jira 8.0.0, Jira now supports the use of the utf8mb4 collation with MySQL databases, while Confluence using MySQL still does not. See the following request: MySQL databases incapable of handling 4byte UTF-8 Characters. Confluence should handle this gracefully

The wording in the documentation should be changed as both databases cannot be setup in the same way with Confluence unable to support the utf8mb4 collation or there should be a disclaimer to advise on using an unsupported collation.