t7004: fix embedded single-quotes

This test uses single quotes inside the single-quoted test
snippet, which effectively makes the contents unquoted.
Since they don't need quoted anyway, this isn't a problem,
but let's switch them to double-quotes to make it more
obviously correct.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7004-tag.sh

@@ -1181,7 +1181,7 @@ test_expect_success \
 	'message in editor has initial comment: remainder' '
 	# remove commented lines from the remainder -- should be empty
 	>rest.expect &&
-	sed -e 1d -e '/^#/d' <actual >rest.actual &&
+	sed -e 1d -e "/^#/d" <actual >rest.actual &&
 	test_cmp rest.expect rest.actual
 '