t1305: avoid comparing extensions

A repository using a hash other than SHA-1 will need to have an
extension in the config file.  Ignore any extensions when comparing
config files, since they don't usefully contribute to the goal of the
test.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t1305-config-include.sh

@@ -63,7 +63,7 @@ test_expect_success 'listing includes option and expansion' '
 	test.one=1
 	EOF
 	git config --list >actual.full &&
-	grep -v ^core actual.full >actual &&
+	grep -v -e ^core -e ^extensions actual.full >actual &&
 	test_cmp expect actual
 '