It could be misleading to keep a signature in a
replacement commit, so let's remove it.
Note that there should probably be a way to sign
the replacement commit created when using --graft,
but this can be dealt with in another commit or
patch series.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>