borgmatic 1.5.19

• #387: Fix error when configured source directories are not present on the filesystem at the time
  of backup. Now, Borg will complain, but the backup will still continue.
• #455: Mention changing borgmatic path in cron documentation.
• Update sample systemd service file with more granular read-only filesystem settings.
• Move Gitea and GitHub hosting from a personal namespace to an organization for better
  collaboration with related projects.
• 1k ★s on GitHub!