BUG #15732: Jessie backports removed from network

The following bug has been logged on the website:

Bug reference: 15732
Logged by: Manfred Torres
Email address: manfredtorress@gmail.com
PostgreSQL version: 9.6.0
Operating system: Ubuntu
Description:

The command "deb http://apt.postgresql.org/pub/repos/apt/ jessie-pgdg main"
fails with error message "W: Failed to fetch
http://deb.debian.org/debian/dists/jessie-updates/main/binary-amd64/Packages
404 Not Found".
Apparently some packages have been removed from the network, please reffer
to
https://unix.stackexchange.com/questions/508724/failed-to-fetch-jessie-backports-repository
for more information.