GHES Raw URL Format Incorrect

Using Github Enterprise Server 3.9.6 with Microsoft.SourceLink.GitHub 8.0.0.

SourceLink is using the `/raw` path on the main GitHub URL when it should be using the `raw.` subdomain.

Example of the URL generated:
https://github.INTERNAL_URL/raw/ORG_URL/REPO_URL/1e045336c6c208f216b8e2b2cbb3036a6f4ab41f/CPlusPlusProject/CPlusPlusProject.cpp

Should be:
https://raw.github.INTERNAL_URL/ORG_URL/REPO_URL/1e045336c6c208f216b8e2b2cbb3036a6f4ab41f/CPlusPlusProject/CPlusPlusProject.cpp

GitHub Enterprise Servers can be configured either way, but GitHub recommends using sub-domains for isolation. I'm not sure if there's a way to detect which is actually in use. I would imagine a DNS lookup to see if the `raw.` domain exists would be sufficient.