cherry-pick, revert: add the --gpg-sign option

Signed-off-by: Nicolas Vigier <boklm@mars-attacks.org>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/sequencer.h b/sequencer.h
index 1fc22dc..db43e9c 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -37,6 +37,8 @@
 
 	int mainline;
 
+	const char *gpg_sign;
+
 	/* Merge strategy */
 	const char *strategy;
 	const char **xopts;