Use `git_config_get_*()` family instead of `git_config()` to take advantage of
the config-set API which provides a cleaner control flow.
Signed-off-by: NTanay Abhra <tanayabh@gmail.com>
Reviewed-by: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>