Fix test broken by r23192

The test in question was working around the ref-counting bug;
removed the workaround.

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@23203 57a11ea4-9604-0410-9ed3-97b8803252fd

src/engine/test/utest-Transaction.c

@@ -466,10 +466,6 @@ test_gnc_transaction_set_get_property (Fixture *fixture, gconstpointer pData)
     g_assert_cmpint (check2->hits, ==, 2);
     xaccTransRollbackEdit (txn);
     test_destroy (txn);
-/* Transaction refs the currency when it sets it but doesn't unref
- * when it's destroyed
- */
-    g_object_unref (curr);
     test_destroy (curr);
     test_destroy (book);
     g_free (t_entered);