We have already done some of this work in master, but we learned after doing it that proxy support would be required for the 2.1.1 release. In order to accomplish this, I will backport some code from master into the pulp-2.1 branch.
This was fixed in https://github.com/pulp/pulp/pull/426
build: 2.1.1-0.1.beta
2.1.1 released