✅ fix test for read only values

test/read-only-values.cpp

@@ -16,8 +16,13 @@ static const json read_only_schema = R"({
 
 int main() {
 	json_validator validator(read_only_schema);
+	try {
 		validator.validate(R"({
 			"debug": true
 		})");
-	return 0;
+	} catch (const std::exception&e ) {
+		return EXIT_SUCCESS;
+	}
+	
+	return EXIT_FAILURE;
 }