I would like to install weblate and reviewing the documentation of version 4 and I read:
"If you are running Weblate on other dabatase than PostgreSQL, you should migrate to PostgreSQL as that will be the only supported database backend in the 4.0 release. The following steps will guide you in migrating your data between the databases. Please remember to stop both web and Celery servers prior to the migration, otherwise you might end up with inconsistent data."
Bitnami provide weblate with MySQL, Do you plan to update the installation to postgresql?