t/t5528-push-default: remove redundant test_config lines

The line

  test_config push.default upstream

appears unnecessarily in two tests, as the final test_push_failure sets
push.default before pushing anyway.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t5528-push-default.sh b/t/t5528-push-default.sh
index 4736da8..69ce6bf 100755
--- a/t/t5528-push-default.sh
+++ b/t/t5528-push-default.sh
@@ -48,7 +48,6 @@
 test_expect_success '"upstream" does not push on unconfigured remote' '
 	git checkout master &&
 	test_unconfig branch.master.remote &&
-	test_config push.default upstream &&
 	test_commit three &&
 	test_push_failure upstream
 '
@@ -57,7 +56,6 @@
 	git checkout master &&
 	test_config branch.master.remote parent1 &&
 	test_unconfig branch.master.merge &&
-	test_config push.default upstream
 	test_commit four &&
 	test_push_failure upstream
 '