t5551: do not assume the "matching" push is the default

Signed-off-by: Brian Gernhardt <brian@gernhardtsoftware.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: Benabik

t/t5551-http-fetch.sh

@@ -13,6 +13,7 @@ LIB_HTTPD_PORT=${LIB_HTTPD_PORT-'5551'}
 start_httpd
 
 test_expect_success 'setup repository' '
+	git config push.default matching &&
 	echo content >file &&
 	git add file &&
 	git commit -m one