Update Mattermost to 5.28.1
Mattermost 5.28.1 is a feature release including some new things such as in-product notices (notifications for things like new versions and features). Some older features like the gif picker and custom emojis are now turned on by default for new installs as well. The full change log is available here as usual.
There are some minor security fixes in this release as well that were previously included in 5.27.1.