unit test: check tx4 conflict error message

src/test/rbf_tests.cpp

@@ -261,7 +261,7 @@ BOOST_FIXTURE_TEST_CASE(rbf_helper_functions, TestChain100Setup)
     // Tests for CheckConflictTopology
 
     // Tx4 has 23 descendants
-    BOOST_CHECK(pool.CheckConflictTopology(set_34_cpfp).has_value());
+    BOOST_CHECK_EQUAL(pool.CheckConflictTopology(set_34_cpfp).value(), strprintf("%s has 23 descendants, max 1 allowed", entry4_high->GetSharedTx()->GetHash().ToString()));
 
     // No descendants yet
     BOOST_CHECK(pool.CheckConflictTopology({entry9_unchained}) == std::nullopt);