test: Replace log with assert_equal in wallet_abandonconflict

This will make the test fail as soon as the bug is fixed, forcing it to
be updated. Otherwise, the bug might be fixed (or made worse)
accidentally, leaving the test in an inconsistent state.

Author: MarcoFalke

test/functional/wallet_abandonconflict.py

@@ -213,7 +213,7 @@ def run_test(self):
         #assert_equal(newbalance, balance - Decimal("10"))
         self.log.info("If balance has not declined after invalidateblock then out of mempool wallet tx which is no longer")
         self.log.info("conflicted has not resumed causing its inputs to be seen as spent.  See Issue #7315")
-        self.log.info(str(balance) + " -> " + str(newbalance) + " ?")
+        assert_equal(balance, newbalance)
 
 
 if __name__ == '__main__':