test: rebase: fix --interactive test

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3404-rebase-interactive.sh

@@ -692,7 +692,7 @@ test_expect_success 'rebase -i can copy notes' '
 	test_commit n2 &&
 	test_commit n3 &&
 	git notes add -m"a note" n3 &&
-	git rebase --onto n1 n2 &&
+	git rebase -i --onto n1 n2 &&
 	test "a note" = "$(git notes show HEAD)"
 '