Re: [PATCH 3/3] transport-helper: fix typo in error message when --signed is not supported

Good eyes.

This one is a straight-forward bugfix for 0ea47f9d (signed push:
teach smart-HTTP to pass "git push --signed" around, 2014-09-15);
will queue directly to jc/push-cert branch and will merge to
maintenance tracks independent from the other two.

Thanks.