Updater: Enhance UI, make build optional

[misch7]

UI: Implement auto-update option and update button

• Add checkbox and button to UI
• Add new parameter autoUpdateCheck to ConfigFile

Bugfix

• Fix OCUpdater: Also change status on network error or invalid XML

Add CMake option BUILD_UPDATER to make the updater optional

• Default: BUILD_UPDATER = NO

  To ease builds for distro packages and contributors (regardless of the specified update URL)

• Enable updater build for Drone CI and AppImage builds

Next steps (follow-up PRs)

• Resurrect auto-update functionality (macOS (Sparkle) work in progress, Windows next)
• Add support for update channels: stable, beta

[misch7]

/backport to stable-2.6

[backportbot-nextcloud]

The backport to stable-2.6 failed. Please do this backport manually.

[misch7]

🍒 Cherry-picked to stable-2.6

[jancborchardt]

Good stuff! :) Since it both deals with the version/updates, the "Updates" section could eventually be rolled into the "About" part where it shows the version. Something like:

Version 2.6.3. Update to 2.6.4 available: [ Download ]
[x] Automatically check for updates [ Check now ]

With "Download" being a button. And when you are up to date:

Version 2.6.4, up to date.
[x] Automatically check for updates [ Check now ]

Also shortened the text, and the "Check now" button should be closer to the text – just like above with the "Ask for confirmation before syncing folders larger than …" and the input box. :)

[jonasgarstick]

So is this enhancement gone again? (can only speak for macOS)

[FlexW]

@jonasgarstick The one in the notification is expected because macOS does not allow to embed links in notifications. For the settings menu I'm not sure. Could you file an issue about it?

[jonasgarstick]

Thanks for your comment @FlexW → #3254