git-send-email: delay creation of MIME headers After the next patch, git-send-email will sometimes modify existing Content-Transfer-Encoding headers. Delay the addition of the header to @xh until just before sending. Do the same for MIME-Version, to avoid adding it twice. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>