9.3 RPMs not signed

Hi, we're receiving the following when updating CentOS 7 hosts to the
9.3.20-3 RPMs:

# yum update postgresql93-libs
...
Dependencies Resolved

================================================================================
 Package                  Arch       Version                   Repository  Size
================================================================================
Updating:
 postgresql93-libs        x86_64     9.3.20-3PGDG.rhel7        pgdg93     205 k
Updating for dependencies:
 postgresql93             x86_64     9.3.20-3PGDG.rhel7        pgdg93     1.0 M
 postgresql93-contrib     x86_64     9.3.20-3PGDG.rhel7        pgdg93     566 k
 postgresql93-server      x86_64     9.3.20-3PGDG.rhel7        pgdg93     3.7 M

Transaction Summary
================================================================================
Upgrade  1 Package (+3 Dependent packages)

Total size: 5.4 M
Is this ok [y/d/N]: y
Downloading packages:


Package postgresql93-libs-9.3.20-3PGDG.rhel7.x86_64.rpm is not signed

# rpm -qpi /var/cache/yum/x86_64/7/pgdg93/packages/postgresql93-* | grep Sign
Signature   : (none)
Signature   : (none)
Signature   : (none)
Signature   : (none)

Please let me know if you need more details.

Thanks.

Michael