Err:1 https://packages.inverse.ca/SOGo/nightly/4/ubuntu bionic/bionic amd64 sogo amd64 4.0.2.20181009-1
404 Not Found [IP: 192.95.20.194 443]
This is SOGo nightly apt repo, old files may be removed and new files will be added every day (or few days), seems this was caused during the change, or old local apt cache data.