This is a minor release part of the 0.12.x.x series.
It contains a fix for the wallet news. It is using now a domain instead of the public ip of the server.
It fixes a problem found with the QCalendarView styles.
The protocol didn't change, so masternode can skip this update. In case you want to update, there's no need to issue the masternode start command.
This release is not mandatory but it fixes some minor bugs. Update if you want to keep getting the pac news on the wallet.