Note that if you are updating from 9.1.3 to 9.1.4 you might get integrity check errors related to a stray extra file
"updater/.gitignore". You can safely delete it then click "Rescan" in the admin page to solve the error message.
-> https://central.owncloud.org/t/web-updater-updates-published-for-8-1-12-8-2-10-9-0-8-9-1-4/6521