t4012: Unquote git command fragment in test title

The command fragments are quoted nowhere else in title texts of
this file, thus make this one consistent with all other titles.

Signed-off-by: Alexander Strasser <eclipse7@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t4012-diff-binary.sh

@@ -31,7 +31,7 @@ cat > expected <<\EOF
  d |  Bin
  4 files changed, 2 insertions(+), 2 deletions(-)
 EOF
-test_expect_success '"apply --stat" output for binary file change' '
+test_expect_success 'apply --stat output for binary file change' '
 	git diff >diff &&
 	git apply --stat --summary <diff >current &&
 	test_i18ncmp expected current