test_config uses test_when_finished to reset the configuration after the
test, but this does not work inside a subshell. This does not cause a
problem here because the first thing the next test does is to set this
config variable itself, but we are about to add a check that will
complain when test_when_finished is used in a subshell.
In this case, "subdir" not a submodule so test_config has the same
effect when run at the top level and can simply be moved out of the
subshell.
Signed-off-by: John Keeping <john@keeping.me.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>