11.21 tag missing and 11 tag points at obsolete version

[NeilW]

$ docker pull postgres:11.21
Error response from daemon: manifest for postgres:11.21 not found: manifest unknown: manifest unknown

$ docker pull postgres:11
11: Pulling from library/postgres
Digest: sha256:5d2aa4a7b5f9bdadeddcf87cf7f90a176737a02a30d917de4ab2e6a329bd2d45
Status: Downloaded newer image for postgres:11
docker.io/library/postgres:11

which is a version using Debian stretch.

[LaurentGoderre]

#1129 fixes this.

[LaurentGoderre]

Looks like this was on purpose to avoid breaking indexes between stretch and other debian versions.

[LaurentGoderre]

Here is the rationale. #582 (comment)

Closing as upgrading has to be a deliberate step.