Restore registry tests as registry moved to external repo

[soltysh]

As part of the 1.8 rebase (4e13893 specifically) removed registry from origin's repository to an external one -> https://github.com/openshift/image-registry.
The problem with that is that some tests where removed along the way, we need to investigate and bring those missing ones back.

[bparees]

@soltysh are you saying we need to enable tests in the origin repo, or in the image-registry repo?

I'm pretty sure @dmage already re-enabled all tests in the image-registry repo, but i'll let him assess this.

[soltysh]

@bparees iirc the idea was to have some of those tests in origin, at least the ones that can and should exist there. @mfojtik might remember the details, as he was the one stripping that part out 😉

[dmage]

@soltysh thanks, I found in this commit 2 more tests.
4e13893#diff-4214e89bfb45549e49735af038578123
4e13893#diff-d1daafcc0a0ef1e009d0dd44848d8ac4

[dmage]

openshift/image-registry#38
openshift/image-registry#39

Feel free to create new issues if you find other tests.

[soltysh]

Thanks!