t4118: be nice to non-GNU sed

Elias Pipping:
> I'm on a mac, hence /usr/bin/sed is not gnu sed, which makes
> t4118 fail.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Ack'd-by: Elias Pipping <pipping@macports.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

t/t4118-apply-empty-context.sh

@@ -23,7 +23,8 @@ test_expect_success setup '
 	cat file2 >file2.orig
 	git add file1 file2 &&
 	sed -e "/^B/d" <file1.orig >file1 &&
-	sed -e "/^B/d" <file2.orig >file2 &&
+	sed -e "/^[BQ]/d" <file2.orig >file2 &&
+	echo Q | tr -d "\\012" >>file2 &&
 	cat file1 >file1.mods &&
 	cat file2 >file2.mods &&
 	git diff |