Merge branch 'cl/rerere-train-with-no-sign' into maint

"rerere-train" script (in contrib/) used to honor commit.gpgSign
while recreating the throw-away merges.
source: <PH7PR14MB5594A27B9295E95ACA4D6A69CE8F9@PH7PR14MB5594.namprd14.prod.outlook.com>

* cl/rerere-train-with-no-sign:
  contrib/rerere-train: avoid useless gpg sign in training

Author: gitster

contrib/rerere-train.sh

@@ -75,7 +75,7 @@ do
 		continue
 	fi
 	git checkout -q "$parent1^0"
-	if git merge $other_parents >/dev/null 2>&1
+	if git merge --no-gpg-sign $other_parents >/dev/null 2>&1
 	then
 		# Cleanly merges
 		continue