Illegal mix of collations utf8mb4_unicode_ci and utf8mb4_unicode_520_ci

I update the WordPress database to use utf8mb4_unicode_520_ci which made the SQL query by Simple History freak out with the error msg in the title. I changed the tables simple_history and simple_history_contexts back to utf8mb4_unicode_ci for the time being which works fine. Would be nice for it to support utf8mb4_unicode_520_ci as well. Thanks a lot for the plugin!