upgrade some error checks I missed to use new assertion failure message

unittests/eosio.system_tests.cpp

@@ -2122,10 +2122,10 @@ BOOST_FIXTURE_TEST_CASE(producer_onblock_check, eosio_system_tester) try {
 
    {
       BOOST_CHECK_EQUAL(0, get_global_state()["total_unpaid_blocks"].as<uint32_t>());
-      BOOST_REQUIRE_EQUAL(error("condition: assertion failed: not enough has been staked for producers to claim rewards"),
+      BOOST_REQUIRE_EQUAL(wasm_assert_msg("not enough has been staked for producers to claim rewards"),
                           push_action(producer_names.front(), N(claimrewards), mvo()("owner", producer_names.front())));
       BOOST_REQUIRE_EQUAL(0, get_balance(producer_names.front()).amount);
-      BOOST_REQUIRE_EQUAL(error("condition: assertion failed: not enough has been staked for producers to claim rewards"),
+      BOOST_REQUIRE_EQUAL(wasm_assert_msg("not enough has been staked for producers to claim rewards"),
                           push_action(producer_names.back(), N(claimrewards), mvo()("owner", producer_names.back())));
       BOOST_REQUIRE_EQUAL(0, get_balance(producer_names.back()).amount);
    }