I think the “ignoring file…” bit is a red herring and not at all related to the problem. /etc/apt/apt.conf.d/50unattended-upgrades is a regular Ubuntu file. It does not regularly have .wcf-dist tacked on the end. That probably means the file was modified, and the distribution version was saved with a “disarmed” filename.
Your packages are up to date and your git files are up to date. The lack of the docker0 device is mildly alarming. If it were my box, I’d probably reboot and try the launcher again.
But that’s me with a long history of Unix, and not so long a history of using Discourse.