build process fails due to outdated package sources

[bh-8]

Building the image using bin/build.sh failed with the following error:

0.860 W: The repository 'http://security.debian.org stretch/updates Release' does not have a Release file.
0.860 W: The repository 'http://deb.debian.org/debian stretch Release' does not have a Release file.
0.860 W: The repository 'http://deb.debian.org/debian stretch-updates Release' does not have a Release file.
0.860 E: Failed to fetch http://security.debian.org/dists/stretch/updates/main/binary-amd64/Packages  404  Not Found
0.860 E: Failed to fetch http://deb.debian.org/debian/dists/stretch/main/binary-amd64/Packages  404  Not Found
0.860 E: Failed to fetch http://deb.debian.org/debian/dists/stretch-updates/main/binary-amd64/Packages  404  Not Found
0.860 E: Some index files failed to download. They have been ignored, or old ones used instead.