The post-update hooks created in t5550-http-fetch-dumb.sh is missing the
"!#/bin/sh" line which can cause issues with portability. Instead
create the hook using the 'write_script' function which includes the
proper "#!" line.
Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>