git_sitrep() shows global git config

[isteves]

As someone in the awkward situation of having 2 GitHub accounts (which is perhaps a problem I need to solve by getting rid of one of them), the git_sitrep() output is confusing when I try to use my secondary account for a project since the name/email are based on the global settings.

Changing global to FALSE here should resolve this problem. If there's a design reason for showing the global settings, perhaps it can be documented. Let me know if a PR would help.

[jennybc]

I think this should probably have a section reporting similar info for local git config, if it detects such a thing.