Fix encoding issue in check_git_config

Fix for
"Unicode equal comparison failed to convert both arguments to Unicode"
when the git username contains non-ascii characters. Fixed by
utf-8 decoding data imported from git.

BUG=521519

Review URL: https://codereview.chromium.org/1301453003

Cr-Commit-Position: refs/heads/master@{#343836}
1 file changed