Replace #23350.
Refactor `setting.Database.UseMySQL` to
`setting.Database.Type.IsMySQL()`.
To avoid mismatching between `Type` and `UseXXX`.
This refactor can fix the bug mentioned in #23350, so it should be
backported.
Change all license headers to comply with REUSE specification.
Fix #16132
Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>
