Description of problem:
this is a regression from 6.4.0-17 (possibly caused by new version of pulp)

a publish fails whenever user tries to publish a content view that includes a CDN repo with applied content view filter.

the error:
RPM1008: Checksum type "sha256" is not available for all units in the repository. Make sure those units have been downloaded.


Version-Release number of selected component (if applicable):
6.4.0-18

# rpm -qa pulp*
pulp-ostree-plugins-1.3.0-1.el7sat.noarch
pulp-selinux-2.16.4-1.el7sat.noarch
pulp-puppet-tools-2.16.4-1.el7sat.noarch
pulp-rpm-plugins-2.16.4-1.el7sat.noarch
pulp-client-1.0-1.noarch
pulp-server-2.16.4-1.el7sat.noarch
pulp-katello-1.0.2-5.el7sat.noarch
pulp-docker-plugins-3.1.4-2.el7sat.noarch
pulp-puppet-plugins-2.16.4-1.el7sat.noarch


How reproducible:
always

Steps to Reproduce:
1. sync a cdn repo
2. create a content view (cv) and add the above repo to it
3. create a content-view package filter (inclusive or exclusive) and put a random (existing or non-existing), random operator and random (valid) value
4. publish a new cv version

Actual results:
unable to publish a content view version: RPM1008: Checksum type "sha256" is not available for all units in the repository. Make sure those units have been downloaded.

Expected results:
no problems, cv version published successfully

Additional info: