Ref T13481. Some older versions of Git appear to not support "--" in these commands. Just drop it. This can lead to ambiguous results with certain obviously-silly remote names, but doesn't appear to lead to anything dangerous.
Will followup with user on ancient Git.
- Only omit "--" in "git ls-remote", since it seems like it's okay for even very old "git config".
It's possible that "--" doesn't work in VERY VERY OLD "git config", but we can always drop it if a user with Rare Beta Git shows up.