This fixes a regression that would have been introduced by commit
a8b927a562 ("import: go: Add an option to use pinned versions.") which is
already 3 years old (!).
* tests/go.scm (fixtures-go-check-test): Register new URL and data for
http-fetch and http-get mocks.
Change-Id: Ie9d306612971de54ce534563731f52baf64bc8e7