Blocked sites no longer have an entry in the matrix

[gorhill]

And hence can't be un-blacklisted from the matrix. To reproduce:

1. Go to wikipedia.org
2. Blacklist wikipedia.org (it's just for the sake of reproducing this bug, wikipedia is great)
3. Tab reloads and shows page as blocked
4. Bring up the matrix
5. Matrix is empty, while it should show wikipedia.org