Clicking View Repository button on a GitHub repository root page produces a 404

Created by: ryan-blunden

• Sourcegraph version: 25366_2018-12-12_18d9b8a (25366_2018-12-12_18d9b8a)
• Platform information: macOS Mojave, Chrome 71.0.3578.80
• Browser extension: v18.12.12.1816

Steps to reproduce:

1. Go to https://github.com/sourcegraph/docsite
2. Click on the View Repository button.

Expected behavior:

To be taken to the root repository page

Actual behavior:

Taken to Sourcegraph 404 page