Finishing touches to fc/transport-helper-error-reporting topic.
* js/transport-helper-error-reporting-fix:
git-remote-testgit: build it to run under $SHELL_PATH
git-remote-testgit: further remove some bashisms
git-remote-testgit: avoid process substitution
Just like all the other shell scripts, replace the shebang line to
make sure it runs under the shell the user specified.
As this no longer depends on bashisms, t5801 does not have to say
bash must be available somewhere on the system.
Signed-off-by: Junio C Hamano <gitster@pobox.com>