git_config: don't peek at global config_parameters
git_config: don't peek at global config_parameters

The config_parameters list in config.c is an implementation
detail of git_config_from_parameters; instead, that function
should tell us whether it found anything.

Signed-off-by: Jeff King <696e3fbcf235d40b6ea1ebd61c87cbea79d444e7@peff.net>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git