info/refs request as described in `http-protocol.txt` and requests that
v2 be used by supplying "version=2" in the `Git-Protocol` header.
- C: Git-Protocol: version=2
- C:
C: GET $GIT_URL/info/refs?service=git-upload-pack HTTP/1.0
+ C: Git-Protocol: version=2
A v2 server would reply: