config wizard does not work if ~/.config/git/config contains include statements

Steps to reproduce:

• Make sure ~/.git does not exist
• Create ~/.config/git/config` with a least two includes, like so:

[include]
path = /path/to/1
path = /path/to/2

Run git-repo config, do the oauth dance.

Nothing is stored.

PS: I think this is a bug in the code that reads and writes git config. If I were you, I'll just run git config --get foo.bar and git config --global foo.bar 42 instead of using a re-implementation of git config parsing in Python.