downloads: drop unused variables from download_mac render
downloads: drop unused variables from download_mac render

We don't reference the project name this way anymore (since it's just
one of many options, we just put the URL in with the content).

Mokolea/git-scm.com,git/git-scm.com,git/git-scm.com,Mokolea/git-scm.com,mosoft521/gitscm-next,mosoft521/gitscm-next,git/git-scm.com,mosoft521/gitscm-next,git/git-scm.com,mosoft521/gitscm-next,Mokolea/git-scm.com,Mokolea/git-scm.com