Log Message:
balsa: Update to 2.5.9

* Balsa-2.5.9 release. Release date 2019-10-19

- fix HTML message layout issues.

* Balsa-2.5.8 release. Release date 2019-10-11

Change with respect to 2.5.7

- i18n improvements.
- improved display of HTML messages.
- handling of calendar (vcal) attachments.
- LDAP address book improvements / error handling.
- message presentation refactoring.
- GPGME is a hard requirement now.
- misc bug fixes and code health updates.